eric houston has been arrested. >> it's weird way human beings are. you can only keep one thing in your head. >> as one spectator put it, it may be gruesome, but it's history. we're making a little news of our own today with the launch of msnbc. >> two decades. >> hello, and welcome to. >> msnbc. more than 175,000 hours of television. >> the judgment of the supreme court of florida is reversed. >> there's a guy with a magnifying glass. >> this is a presidential election. >> countless news events. >> there were parents who suddenly were afraid to send their children to school. >> they were just trying to stop the economy from going into depression. >> history in the making. >> change has come to america. >> the goal was to make music available to everyone. >> this is a total victory for the advocates of same-sex marriage. >> how does what happened then

impact us now? >> katrina is always in the back of their minds. >> this was a human catastrophe on the broadest level. >> tonight, america is at war with terrorists. >> 9/11, it defined the lives of an entire generation. >> "20 stories that shook the world in 20 years." >> hi, i'm rachel maddow for msnbc. for the last 20 years, msnbc has covered all the biggest news of our time from what seemed like a never-ending presidential election to a devastating attack on our nation. two decades of events that have transformed not only the way we report as journalists but the way we live. the way we love. the way we learn. right now, 20 events that made headlines and changed us. >> 9/11 continues to change everyday life in this country.

>> i was putting on my microphone to do my show on msnbc, and somebody said a plane has hit the world trade center. >> there was a major incident in lower manhattan. a plane has crashed into one of the upper floors of the world trade center. >> the airplane is clearly a commercial airliner of some sort. >> it was a crystal clear day. nothing added up. there's a moment where your mind, you know, goes to "this could be terror." >> and i don't think that we started to get a lot of clarity, frankly, until the second plane hit. and the second the second plane hit, i think all of us knew that it was terrorism. >> terrorists fly a third jetliner into the pentagon.

a fourth hijacked plane crashes in a pennsylvania field. by 10:30 a.m., the twin towers have crumbled. >> tonight america is at war with terrorists after a stunning series of attacks today. >> that day took everything that i knew as a journalist, as a citizen, as a father, as a husband, as someone who had been in the business for 40 years. >> make no mistake, the united states will be hunt down and punish those responsible for these cowardly acts. >> the attacks claim the lives of nearly 3,000 people from 93 countries across the globe.

>> it was an enormously consequential event that led to a series of other events that didn't just define the last 15 years. it defined the lives of an entire generation. >> everything seems to revolve back around 9/11. when you stand in those long lines at tsa, it's 9/11. when you get frisked going into a ball game, it's 9/11. it changed our lives and everything we do. the country went from being ripped with grief to on a war footing in a very short span of time. >> less than a month after september 11th, a u.s.-led coalition launches air strikes in afghanistan, marking the start of the longest war this country has ever seen. >> you're either with us or you're against us in the fight against terror.

>> in march 2003, the u.s. wages war on iraq after president bush and his administration make the case that saddam hussein is hiding weapons of mass destruction, an allegation that is latter proven to be false. >> to learn later that those did not exist in iraq at the time of the invasion really threatened how many americans viewed truthfulness in government, threatened the bush presidency and damaged u.s. relations around the world. >> saddam hussein is captured in 2003 and executed three years later. in 2011 u.s. forces kill 9/11 mastermind osama bin laden. >> his death does not mark the end of our effort. there's no doubt that al qaeda will continue to pursue attacks against us. we must and we will remain vigilant at home and abroad. >> 15 years after 9/11, thousands of u.s. troops remain

in iraq and afghanistan. >> we have people now fighting in afghanistan and fighting still in parts of iraq who were 3 years old when the attacks took place. >> in recent years, a deadly new threat emerges. the islamic state also known as isis. >> without the iraq war, there is no isis. isis is simply insurgents who were more or less defeated but who then found a way to reinvigorate their organization. >> isis is armed and funded like no terrorist group in history. >> in the battle with isis, the theater of war has expanded still most recently to the west where the terrorist organization executed coordinated attacks in paris in 2015 and in brussels in 2016.

>> there is a line you could draw from 9/11 to the isis directed atrocities in europe. we cover them now like they are great anomalies and great tragedies which, of course, they are. but i think going forward, they're going to become more commonplace. coming up -- >> people started defaulting on these loans. you know, these homes started getting foreclosed on, and it was like a domino effect, and all of that bad credit then was sort of filtered throughout the financial system.

the internet makes life so much simpler now, we can point and push and have a few clicks and order almost anything you can imagine. >> before the internet, we bought books in a bookstore and soap in a drugstore, but the rise of the on demand economy has turned traditional business models upside down.

>> the on demand economy means you're operating faster, and faster means you're more efficient. >> in 1997 online book retailer amazon.com goes public, ushering in a profitable new era of digital commerce in a 24/7 marketplace, but books are just the beginning. > on demand economy has been changed by two things. one is your phone and the other is satellites in the sky. so they always know where you are. uber obviously is the most extreme example. i could call a car to wherever i am at any time. >> everybody expects to get whatever they want at the touch of a button and they want it right now and they can get it. >> i did not have sexual relations with that woman, miss lewinsky. >> a year into his second term, president bill clinton goes live on national television to address reports about an affair with a white house intern.

>> bill clinton brought the presidency to a place where it had never been. standing up there and saying i did not have sexual relations with that woman, a sentence that instantly become memorialized by the entire country and a sentence that was also a lie. >> the allegations are very, very serious. if those turn out to be true, this presidency is in serious trouble. >> so much of it was salacious, and so much of it was tabloid. at some point you had to step back and say, the future of the leader of the free world is at stake. >> six months after lying to the country, president clinton confesses to his indiscretions in a primetime broadcast. >> indeed i did have a relationship with miss lewinsky that was not appropriate. in fact, it was wrong. >> in december 1998 the house of representatives impeaches president clinton, charging him with obstruction of justice and lying under oath. >> i do. >> certainly having the kind of affair that he did was repugnant

to almost every american that a president would do that in the white house, but was it a high crime and misdemeanor that would force him from this office. >> after a five-week trial, the senate reaches its verdict. >> the president acquitted on two counts perjury and obstruction of justice. >> 18 years later, the scandal still dogs the clinton family as hillary clinton becomes the first woman in u.s. history to be the presumptive nominee of a major political party. >> do you remember the famous "i did not have sex with that woman?" she's taking negative ads on me. >> monica lewinsky fair is going to affect this next election in a big way. >> it is a challenge for hillary clinton because it takes away from who she is as an office holder herself. in one the greatest comebacks of all time, steve jobs returns to apple as interim ceo in 1997 after being fired 12

years earlier in the company he found. >> steve jobs coming back to apple is the smartest decision that company ever made. >> let's chat what we're trying to do here. >> i think being fired fed the fire so to speak. he was going to show these people who let him go what he was going to make of this country. >> this is going to be the hottest gift. >> in the years that follow, apple rolls out a spread stream of user-friendly products, turning it into one of the most successful companies in history. >> steve is indisputably the leader of this transformation to consumer products in our industry. >> i everything. ipod, imac, ibook. now iphone. >> i just take my finger and slide it across. >> they made technology that we actually wanted to use and that was intuitive to learn and they really made it a much more consumer-friendly space. >> in 2011 steve jobs dies from pancreatic cancer.

he leaves behind a company that has changed the world. >> i think it's hard to overstate the influence of apple on all of our lives over the past 20 years. good evening. this has been a wild and harrowing and history-making day, and we still don't know how this ends. >> in 2008 america's housing bubble bursts, triggering our nation's worst international disaster since the great depression. >> virtually all the big banks, they made big, big bets on subprime mortgage bonds and they were wrong. the bonds were bad and they didn't see how bad they were. >> the fallout is catastrophic from individual americans to the nation's largest banks. >> the financial crisis happened because people got mortgages too easy and bought homes they shouldn't have been buying. >> people started defaulting on these loans. you know, these homes started getting foreclosed on, and it was like a domino effect, and all of that bad credit then was sort of filtered throughout the

financial system. >> bear stearns is rescued from impending bankruptcy by jpmorgan chase in march 2008. six months later the u.s. government takes control of the nation's top mortgage giants, fannie mae and freddie mac. lehman brothers collapses without warning and insurance company aig is seized by the fed, signaling that the entire u.s. financial system is on brink of failure. >> the government's response to the crisis was peripatetic. problems rolled in and they dealt with them on a case-by- case basis. they were just trying to stop the economy from going into a depression. >> in an effort to stabilize the economy, congress approves a controversial $700 billion bailout. >> this is truly a monumental moment in american history. >> their view was you can't just let it all go down because if the banks go down, then the economy is in chaos. >> a lot of people lost their homes and a lot of people lost their jobs. and eventually you saw people

downsize and it shook out to where it ought to have been from the start. >> the bailout under the bush administration is perceived by many conservatives as government overstepping its bounds, and protesters launch a new movement with an old history. >> we're thinking of having a chicago tea party in july. >> that's where the tea party movement was really born. they saw wall street getting a bailout when they weren't bailed out. nobody found them a new job. nobody made sure their employer was solvent, so that really got people upset. >> the tea party quickly took off, and in 2010 it helps the gop capture the house. >> the tea party morphed into something entirely different. it's become this sort of free floating vessel that collects anger and anxiety wherever it goes and runs on that as fuel. but the beginning is the financial crisis. coming up -- >> instead of trading cassettes which we had been doing, suddenly songs are flying around for free like crazy.

it has been an exhausting and quite an emotional ride tonight. >> the world watches as polls close across america in the 2000 presidential race between texas

governor george bush and vice president al gore. just after 2:00 a.m., news networks project a winner. >> barring any recount or any anomalies, george w. bush, the governor of texas, is projected now to win the presidency of the united states. >> al gore was on his way to make a concession speech, and en route, they got information that it was closing again the other way. >> i've just gotten off the phone. it is true that the vice president has called to recap the his concession. >> the race it turns out was too close to call. >> just an hour or so ago, the tv networks called this race for governor bush. it now appears -- it now appears that their call was premature. >> the system just simply broke down. i looked into the camera and said we not only have egg on our face we've got omelet all over our suits. it is not over, ladies and gentlemen.

>> al gore leads in the popular vote, but the electoral college is in a dead heat, and it all comes down to one state. >> florida was the place where it was close enough to have a recount and have the right number of electoral votes to change the outcome. that's when we discovered how imperfect the voting system is. >> it varies across the country. voting methods vary. some people punch cards, throw levers. it's all different. >> with reports of widespread voting irregularities, the florida state supreme court orders a manual recount in several counties. >> they would hold up ballots and stare at it, both sides, and say, what did this voter mean? >> when one woman would say that's a gore vote, and the other guy would look at it and say, no, that's a bush vote, they were looking at the same ballot. >> when you punch the little hole in the card, the little square that gets punched out they call that the chad, doesn't

come all the way off. so the question was, how should a hanging chad, they called it, be interpreted. >> there's a guy with a magnifying glass looking at ballots and chad. i'm like, this is where we're at? this is a presidential election. >> the bush campaign objected to the recount in a series of lawsuits that ultimately reach the united states supreme court. >> we got the decision. we ran outside and then we stood there on live television trying to figure out what it was. and it did occur to me at the moment that it was not a good one to screw up. >> the judgment of the supreme court of florida is reversed. >> 36 days after the election, the u.s. supreme court votes 5-4 in favor of stopping the florida recount. the controversial decision in effect hands the presidency to george w. bush. >> people liked the winner were very happy and thought this was great legal scholarship. >> whether you vote ford me or not, i do my best to serve your

interests and i will work to earn your respect. >> and people who didn't like the outcome thought this was rigged. >> i say to president elect bush that what remains of partisan rancor must now be put aside, and may god bless his stewardship of this country. >> the decision by the supreme court underscored in many ways the power of the electoral college. i think it also led to a lot of cynicism in the electoral process. >> 16 years and three presidential elections later, the 2016 race for the white house problems that the process is still anything but predictable. >> the risk for irregularities in voting still very real and certainly those who work in election law have gotten more sophisticated how they're ready to battle this out if it comes to that. the huge battle in the music industry these days against the internet site known as napster.

>> sean parker and john fanning launched the music file sharing service napster in 1999. >> the goal was to make music available to everyone. >> the site blind-sides the record industry and permanently transforms the way music is distributed and sold. >> instead of trading cassettes which we had been doing, suddenly songs are flying around for free like crazy. >> at its peak, 70 million users are swapping songs on napster, costing the record industry hundreds of millions of dollars in lost revenue before the service is forced to shut down in 2001. >> we started a kind of cultural revolution but didn't succeed as a business. >> nearly two years after napster's demise, apple launches the itunes market store, an online marketplace that redefines the single. >> i can't remember the last time i bought an entire album. you know, it's an a la carte menu out there. >> today subscription-based streaming services are edging

out digital downloads by selling access to massive music catalogs stored in the cloud. >> i think most people in the music business have no idea what the future will be. there's all these technological challenges to profitability, and they don't know how to combat that. >> while researching treatments for high blood pressure and heart disease, the drug company pfizer accidentally develops a life-changing little blue pill. in 1998 viagra is approved by the fda. >> it turns out there was a side effect that a lot of the initial patients had. they developed elections, and the pharmaceutical companies quickly realized that's a much better place for us to market than just another blood pressure pill. >> it was a big deal because it treated erectile function and made that condition part of the national conversation. >> sales of viagra have quadrupled since its launch, but there is still no equivalent for

the on half of the population. coming up -- >> it did introduce a new era, if you will, of mass shootings at schools.

a wildfire north of los and they open fire. >> i just started screaming and crying and telling them not to shoot me. and so he shot the girl. he shot her in the head in front of me. the midmorning massacre

captured on school security cameras claims the lives of 12 students and one teacher before the shooters turn their guns on themselves. >> there were parents thousands of miles away from columbine high school who were suddenly afraid to send their children to school. >> it really did introduce a new era, if you will, of mass shootings at schools. >> since 1999 there have been more than 250 school shootings in this country. the 2007 massacre at virginia tech kills 32 people. in 2012 six faculty and 20 first graders are killed at sandy hook elementary in newtown, connecticut. >> i will never forget the day i drove into newtown. one of the first houses i saw had christmas lights strung. i had this realization that

there were christmas trees in houses with presents under them for children who would never open them. at that moment i thought how can we as a nation deal with this again with the senseless loss of precious young life. >> four months after sandy hook, a bill banning certain military-style weapons fails in the u.s. senate and mass shootings continue to take place all over our country. >> somehow this has become routine. the reporting is routine. my response here at this podium ends up being routine. the conversation in the aftermath of it, we've become numb to this. >> innocent people are killed in movie theaters, in houses of worship, and most recently at a gay nightclub in orlando, florida.

>> our collective sense of security was shattered again today by terror. >> oh, my god. people are getting shot, dude. oh, my -- >> 49 people are killed and another 53 injured in what is the worst mass shooting in u.s. history. >> mass shootings in this country have certainly affected the debate about gun control but not in the ways many people think. and we've seen in certainly the last several mass shootings that gun sales tend to go up as the conversation once again focuses on guns and their availability and how they may or may mot have contributed to, you know, the latest horror. the advent of modern technology has introduced a new generation of virtual vigilantes, fueling the ongoing debate about personal privacy versus national security. >> wikileaks took on the u.s. military and started leaking documents and videos from the military's own servers.

>> in 2010 whistleblower website wikileaks publishes a highly classified video filmed from a u.s. apache helicopter showing a 2007 air strike that kills 12 people including civilians. >> he's wounded. >> oh, well. >> there was something jarring about being able to see something that feels like we shouldn't be seeing but also that we had to see. how many other incidents are there like this that we're not seeing. >> three years later, former nsa contractor edward snowden leaks classified u.s. government documents to a british newspaper revealing controversial u.s. surveillance practices including the tracking of phone records of millions of americans. >> this needed to be told to the public. you know, the constitution of the united states has been violated on a massive scale. >> facing espionage charges in if the u.s., snowden flees to russian and is granted asylum.

a federal court decides that the nsa's surveillance program collecting bulk phone metadata is illegal. >> you can see how people don't want to have their private lives looked into, and you can also see how the law enforcement agencies lost a very powerful and very effective tool. >> this is something that the country's only coming to grapple with, which is we want our privacy. but, you know, we're going to have some trade-offs here. we have he to decide what those are and we haven't yet. nearly 1.7 million americans will be diagnosed with cancer in 2016. since the early '90s, the death rate from the disease has dropped by 23% in the u.s. >> the medical community will never encounter a more vicious militaristic enemy than cancer. >> after decades of clinical trials, in 2015 the fda approve as powerful new weapon in the

war on cancer. a treatment called immunotherapy. it uses the body's own immune system to fight cancer. >> they've gotten a big interest in cancer because i'm in remission, but it's there, and everyone that i talk to in the field says that we're on the cusp of the golden age and it's by immunotherapy about using your own body to fight the cancer in your body. >> right now, immunotherapy is being used successfully to treat melanoma skin cancers as well as lung cancers. >> vice president joe biden is leading the charge to accelerate cancer research after losing his 46-year-old son beau to brain cancer. >> i learned so much from so many of these brilliant brilliant docs that i began to realize that they're right, they we are at an inflection point and we need something to push it over. coming up -- >> we rely on government in times of crisis, and it failed. it failed a lot of people.

august 29th, 2005, hurricane katrina slams into the gulf coast. deteriorating levees in new orleans are breached. floodwaters pour into the city.

>> there were neighborhoods where homes were literally wiped from the face of the earth. >> we hitched a ride on one of these airboats. as we were going down this street -- or river, i should say, you realized as you were looking at these homes that everybody's still home. >> they've got people in three-story houses still trying to survive in the houses. >> what started as a natural disaster quickly becomes a national tragedy. >> the call went out to evacuation, but there are communities where people don't have cars and they don't have access to a lot of the notifications. >> more than 20,000 residents seek refuge at the new orleans superdome, only to find deplorable conditions, mass confusion, and little help from local or federal authorities. >> the only thing angrier than katrina are the thousands of hungry, tired and thirsty that katrina left in its wake.

>> that was the most graphic show of how it was almost okay to do this to certain people of a certain class and a certain race. >> how could they leave us like this here? we have nothing. >> i don't know where i'm going to end up. >> this was a human catastrophe on the broadest level. there were moments where you just had to sit down for a couple minutes and just, you know, accept the humanity of it, how sad this was. that was hard. >> from local missteps to fema neglect to president bush's seeming disconnect to the gravity of the situation. >> and, brownie, you're doing a heck of a job. >> the government response is under fire. >> i drove all the way down to the coast and just drove up and down, and i kept commenting, where are the police officers? where's the national guard? they were nowhere to be seen.

>> look, we right here. >> i got you, madam. we're right here. >> in the end, nearly 2,000 lives are lost and a million people are displaced. >> on the local, state, and federal levels, they have clearly learned the lessons of katrina. katrina is always in the back of their minds with every storm that approaches. they evacuate people faster. they react much quicker. >> we rely on government in times of crisis to protect us, and it failed. it failed a lot of people. it was shameful. since 1992 world leaders have convened every year to discuss ways to fight climate change. in 1997 a treaty called the kyoto protocol is drafted in an effort to cut carbon emissions worldwide, but the u.s. won't support it, and it fails. nearly a decade later, "an inconvenient truth" has its premiere. >> i am al gore. i used to be the vice president

of the united states of america. >> the film shines a spotlight on global warming and on vice president gore's climate change activism. >> is it possible we should prepare on other threats besides terrorists? >> what al gore did was create a really simple but entertaining film that explained the science in way that almost anybody could understand. >> what "an inconvenient truth" did is it got people curious enough that they were willing to figure out exactly what climate change or global warming is. >> 17 years after the failed kyoto protocol, 195 countries sign the paris agreement, promising to limit global warming to well below 2 degrees celsus. >> we are going to win this. the remaining question is how quickly we will win it.

it is 10:50 p.m. on the east coast of the united states, and we've been following the car accident this evening in paris, france. >> reports of a serious car accident involving princess diana and the paparazzi stun the world. >> it was looking more and more likely princess diana had died. when the time comes to say that, it's emotional. it's hard. >> princess diana has died, according to the british news agency "press association." >> she had captured the imagination of people around the world on so many levels, that it really did become like a global tragedy. >> and i think people mourned that because they felt they lost someone they knew. >> princess diana's life is cut short, but her impact on the british monarchy endures. >> she showed a humanity that the royal family hadn't shown in a very long time. >> nearly two decades later, the public embraces an increasingly

accessible royal family. >> they are gracious and friendly and courteous and human. by 1994, aids is the leading cause of death for all americans between the ages of 25 and 44. two years later, a life-saving breakthrough for the more than half a million americans living with the disease. a complicate and expensive cocktail of anti-retro viral drugs. >> once this treatment hit the market, we saw dramatic decline and the death and diseases due to aids. in fact, whole hospital wards closed down that were devoted to hiv and aids. >> we now have the ability to promise to most people who have hiv they can have a near normal life expectancy and quality of life. >> with 37 million people worldwide living with hiv and aids, the challenge now is access to the treatment.

>> hiv and aids is still a major public health concern because of limited resources and access to these medications. there's still a long way to go in terms of prevention and treatment. coming up -- >> don't shoot. don't shoot. >> you saw this conversation about, do we value the lives of young black men? are they sort of the throw-away parts of our society?

if there is anyone out there who still doubts that america is a place where all things are possible, tonight is your answer. >> november 4th, 2008, an extraordinary moment in american history. >> this was the first breaking of the mold. >> barack hussein obama is

elected the 44th president of the united states and becomes the nation's first african-american chief executive. >> i think the world said america has come of age, to think that this nation who had the legacy of slavery and segregation, had elected a black president. >> i thought he was a statement for this country that was such a good, powerful thing, the sense of optimism, and, my god, this is a really great country. >> obama energizes the electorate through a sweeping campaign, promising hope and change. behind the scenes his team leverages the power of big data to target voters and secure his victory in the landmark election. >> president obama got through multiple hurdles. number one, the doubts that even african-american voters had as to the viability of black candidates. number two, the lack of name recognition and that name. barack hussein obama. >> it's been a long time coming,

but tonight, because of what we did on this day, in this election, at this defining moment, change has come to america. the rise of the internet in the late '90s yields a company that begins in a california garage and goes on to unleash the power of the worldwide web. >> google grew with the scale of the internet. and we were amazed at the number of contributors, the amount of content. >> nearly a decade after the domain name is registered, google is a technology giant, and the word "goggle" becomes so ubiquitous that it is added to the dictionary. >> we have on the order of 3 billion people connected to the internet. virtually all of them use google probably once a month, and on a daily basis it would be in the billions. in 2006, facebook opens to the general public and launches a social media revolution.

>> here's a company that grew out of a college dorm room that now has over a billion people on planet using it. >> today social media shows explosive growth. >> twitter, pinterest, facebook, instagram. the biggest thing is social media makes you think of yourself as a brand. >> it makes the world a smaller place, fundamentally changing the way we communicate and organize. >> all of these tools have done is they've harnessed groups and passions to in the same sense that we celebrate the use of facebook, twitter, and others, it's also true that opposition infiltrates those and knows exactly what everyone is doing, so it goes both ways. outrage erupts in 2012. when trayvon martin, an unarmed teenager, is shot and killed while walking down the street in florida. a man named george zimmerman is charged with second-degree murder.

a year later at trial, zimmerman claims he acted in self-defense, and he's acquitted. those who oppose the ruling unite and launch the national movement "black lives matter." >> the black lives matter movement was born out of a need to affirm black life in a day and age where we were seeing senseless killings of unarmed black people. >> you saw this conversation about do we value the lives of young black men? are they sort of the throw-away parts of our society, that they can be killed without consequence? >> in 2014 a ferguson, missouri, police officer shoots and kills michael brown, another unarmed black teenager. the officer says he feared for his life. >> what's striking to me was the sheer fury, frustration, and rage of folks who lived there. >> we were on the air and they were shouting things at us like, you know, why are you here now, we've been here for years.

why are you just showing up? >> and they were furious. they were pissed off at the police. and a bunch of young men started chucking rocks. >> you know what? >> they're chucking rocks at us. >> you know, we are telling it the true story. >> people are angry, man. they're real angry. >> i think people in that community felt so ignored and undervalue and trodded upon for so lock long, then all of a sudden, there's the glare of national media attention that wasn't capturing the reality, and people were enormously frustrated by that. >> each death and custody fuels the black lives matter movement, cameras were capturing the final days of people like walter scott, freddie gray, sandra bland. >> there have always been police and citizen altercations that are controversial, but we're leaving in an era now, where information is getting out there

so rapidly through social media. >> now the observer is the cell phone. any civilian can tape a police encounter and really create a set of facts that are an eyewitness account. >> in one devastating week earlier this month a video circulates online of police killing alton sterling in louisiana. less than 48 hours later, philando castile is shot dead during traffic stop in minnesota. his girlfriend streams the aftermath live on facebook. >> the officer just shot him in his arm. >> the next evening a peaceful black lives matter protest erupts in chaos when a sniper ambushes the police and kills five officers. nine officers and two civilians are wounded. >> all i know this -- this must stop, this divisiveness between our police and our citizens.

i find it implausible that two men deciding to commit themselves to each other, threaten the marriage of people a couple blocks away. >> in 1996 president bill clinton signs the defense of marriage act, a divisive law banning federal recognition of same-sex marriages. >> we're here, we're queer. >> doma, as it's known, ignites a two-decade battle over equal rights. >> it said, first of all, if one state declares the right to same-sex marriage, no other state has to honor that. and the second thing it said is if a state decides to grant same-sex marriage, the federal government cannot recognize that right. >> in the years after doma, 31 states passed laws or constitutional amendments to ban same-sex marriage. in some cases, states do both. >> to insist that male/male, or female/female relationships must have the same status is patently

absurd. >> but proponents of equal rights forge ahead. in 2000 vermont recognizes civil unions, and by 2003 same-sex marriage is legalized in massachusetts. conservative backlash is fierce and sweeping. >> our nation must enact a constitutional amendment to protect marriage in america. >> it's been pretty incredible how quickly the issue of same-sex marriage has moved in 2004. >> by 2012 same-sex marriage is legalized in six states and washington, d.c. >> watching vice president biden come around on this issue before the president was an incredible moment on a number of levels. >> i am absolutely comfortable with the fact that men marrying men, women marrying women, and heterosexual men and women are entitled to the same exact rights.

>> in 2015 a monumental and unambiguous decision. the united states supreme court rules that the constitution guarantees the right to same-sex marriage. >> this is a total victory for the advocates of same-sex marriage. >> today we can say in no uncertain terms that we've made our union a little more perfect. >> just a little more perfect. as we've seen over the last 20 years, this country and the whole world have been shaped by key players and major events, and at times, change has been good, at times change has been slow, and sometimes change is very unwelcome. but as we reflect on the past 20 years, we're also looking forward to the future, to the next 20 years. i'm rachel madow, thanks for watching. >> where are we going to begin?

>> i think we should begin day one, msnbc. >> oh, yeah. where else? >> it was bare bones, nerve wracking. >> i can't believe it's been 20 years. msnbc was such a cutting edge place whether he it went on the air. >> favorite msnbc memory? >> she does not have a short memory. i have a short memory. >> thank you so much, reverend. >> thank you los angeles is bracing for a second night of burning, killing and looting. >> the stories you're about to see were recorded in the news between april 29 and may 1, 1992. >> it was a stunning thing to see, tanks rolling down the streets in los angeles. >> can we all get along? >> jeffrey dahmer came back to face justice. >> 15 bodies preserved in a refrigerator. >> it happens all the time. there are lots of other really