Transcript for Obama's Farewell Address: 'It Has Been the Honor of My Life to Serve You'
President Obama delivering an emotional farewell address tonight, calling on the American people to stay engaged and hopeful. Expressing faith in America's next generation of young leaders. Tonight we reflect on his inspiring words and the legacy he leaves behind. Here's ABC's David Wright. Reporter: Tonight in Chicago -- Hello, Chicago! Reporter: A hero's welcome for the 44th president. We're on live TV here, I gotta move. Reporter: A favorite son of the windy city, now on hisast lap. Yes, our progress has been uneven. But work of democracy has always been hard. It's always been contentious. Sometimes it's been bloody. For every two steps forward, it often feels, we take one step back. Reporter: Fitting that Barack Obama should give the last speech of his presidency here -- Four more years! I can't do that. Reporter: Chicago is the city that launched him. A junior senator on the rise, his hair darker, his kids younger. Hello, Chicago! Reporter: Hopes raised so high, he was practically destined to disappoint the audacity of hope, confronting first the gridlock of Washington. The reforms I'm proposing would not apply to those who are here illegally. That's not true. Reporter: And now the reality -- You're fired. -- Of a roll back. In his exit interview with George Stephanopoulos, his insisted his legacy isn't all lost. My hope is that the president-elect, members of congress from both parties look at where have we objectively made progress, where things are working better. Don't undo things just because I did them. Reporter: A few things he accomplished can't be taken away. ??? At last ??? Reporter: First and foremost, just being America's first black president, he made history just by winning the election. The farther we get from his honeymoon, it's easy to forget that. I grew up in the '70s. People thought that in your lifetime, we would never see an African American as president. I have a daughter who's 13. I don't think she remembers anything but having an African American as our president. Reporter: Christian champagne was a high school junior when he first met the president. He came and it was one of the greatest moments of my life. Reporter: Obama paid a visit to becoming a man, a non-profit support group, helping to bridge the opportunity gap for young man in Chicago's public schools. In that circle, champagne and Obama found they had something in common. They both grew up without fathers. What does it mean to have a president who looks like you? It would be more influential. Someone you could look up to, other than a sports star. But having a president that's African American and is from Chicago, it gives you a big sense that you could actually make it, that the American dream is true. It's been a powerful symbol to have a black president, one that's long overdue, and yet, there's a sense out there, that race relations are worse now than twhen he took office. What do you make of that? I think when we think about that slogan, about hope and change, when I work with my young men, I tell them there's always going to be issues and things we have to think about. Reporter: Tonight Obama himself acknowledged the racial divide still looms large. After my election, this was talk of a post-racial America. And such a vision, however well intended, was never realistic. Reporter: Another accomplishment that history books are sure to include, killing America's number one enemy. The United States has conducted an operation that killed Osama bin laden, the leader of Al Qaeda. Reporter: But critics would say, you have to balance that against the fact that Obama underestimated the threat posed by ISIS. His legacy, judged by what he accomplished, tends to be mixed. He fulfilled his campaign promise to turn the page from the bush years on American foreign policy, and stressed diplomacy rather than war. He re-opened a dialogue with Iran and Cuba. And turned a P with the Arab world. I've come here to Cairo to seek a new beginning between the United States and muslims around the world. Reporter: Obama promised to end the wars in Iraq and Afghanistan and technically he did, but we still have troops on the ground in both countries. American drones have killed thousands of people by remote control. The ghoul ag in Guantanamo is still open for business. The Middle East, engulfed in conflict. And the prospect of peace between Israel and palestine, seems now more remote than ever. Domestically he's been a powerful voice when the nation mourned, channeling moral authority one mass shooting after another, after another. ??? Amazing grace ??? Reporter: And yet, beyond the words, beyond that spiritual, he clearly sang from the heart in Charleston. What concrete measures can he point to that might reduce gun violence in the future? He has said that one of his biggest regrets and not being able to pass any meaningful gun control reform. And it remains one of the biggest failures of his presidency. He's articulated a sense of frustration and rage and disappointment, and yet he hasn't been able to do anything about it. Who do we blame for that? I think there's a lot of people working on the problem. I'm one of the people working on the problem. There's great testimonies and stories about people who have overcome violent outcomes. You don't necessarily hear about those. You hear about the gun shots and the violence and the bloodshed. Reporter: Other things Obama did accomplish or influence are now under threat. This morning the supreme court recognized that the constitution guarantees marriage equality. Reporter: His turnaround on the topic helped make lgbt struggles mainstream. And Obamacare, now at the mercy of the man Obama felt free to mock just a few years ago. No one is happier, no one is prouder to put this birth certificate issue to rest than the Donald. That's because he can finally get back to focusing on the issues that matter. Like, did we fake the moon landing? What really happened in Roswell? And where are biggie and tupac? Reporter: Trump has made it clear, the first issue he'll target is Obama's biggest domestic accomplishment. We're going to repeal and replace Obamacare. We have no choice. Michelle? Reporter: Tonight, the president couldn't help but get emotional, with a special shout-out to the first lady. For the past 25 years, you have not only been my wife and mother of my children, you have been my best friend. You have made me proud, and you have made the country proud. Reporter: A new poll finds Obama is going out on a high note. His highest approval rating in seven years, 55%, as he gets set to retire. Meanwhile, 51% disapprove of trump's performance so far as president-elect. But 52% say they're optimistic. God bless you, and may god bless the United States of America! Reporter: Change can be healthy. Obama proved that eight years ago, and reminded his supporters tonight to keep an open mind. You believe in a fair and just and inclusive America. You know that constant change has been America's hallmark, that it's not something to fear, but something to embrace. You are willing to carry this hard work of democracy forward. You'll soon outnumber all of us, and I believe as a result, the future is in good hands. Reporter: Soon enough, we'll see if the new guy is offering change for the better. For better or worse, in our system, there are limits to how much any one man can do. Obama proved that too. I'm David Wright for "Nightline" in Chicago. ??? ???
This transcript has been automatically generated and may not be 100% accurate.