CHICAGO (AP) — In his parting message to the nation, President Barack Obama is declaring his continued faith in the ability of all Americans to bring about powerful national change, despite the trials of the last eight years that so often stood between him and his goals.

Obama, standing before thousands in his hometown, Chicago, planned to reflect on his origins as a community organizer who witnessed “the quiet dignity of working people in the face of struggle and loss.” He argues change is only possible “when ordinary people get involved” and join forces to demand progress.

“After eight years as your president, I still believe that,” Obama says in excerpts of his speech released in advance by the White House. “And it’s not just my belief. It’s the beating heart of our American idea — our bold experiment in self-government.”

Now an elder statesman, Obama returned to the city that launched his unlikely political career to bring his eight years as president to a close. His speech at Chicago’s McCormick Place will be his last chance to try to define what his presidency meant for America.

It’s a fitting bookend to what he started in Chicago. It was here in 2008 that the nation’s first black president declared victory, and where over the years he tried to cultivate his brand of optimism in American politics.

In his speech, Obama planned to invoke the Declaration of Independence’s teachings about equality and unalienable rights, and its challenge to Americans to take it upon themselves to defend those rights and improve America’s democracy.

“This is the great gift our Founders gave us,” Obama planned to say. “The freedom to chase our individual dreams through our sweat, toil, and imagination — and the imperative to strive together as well, to achieve a greater good.”

The president arrived in Chicago in the evening joined by an array of long-serving White House advisers and people from his past, including sister Auma Obama from Kenya. First lady Michelle Obama, daughter Malia and family friends came along for what the White House said was Obama’s 445th mission aboard Air Force One.

Obama has said he’s leaving his eight years in office still confident that the democratic system responds when dedicated citizens make their voices heard. The system did respond, in November, to Americans who by and large rejected Obama’s policies by electing Republican Donald Trump.

Obama and Democrats had warned against a Trump presidency in apocalyptic terms. So now Obama’s daunting task — the closing act of his political career — is to explain how his vision of America remains relevant and achievable for Democrats in the Trump era.

No stranger to high-stakes speeches, Obama rose to national prominence on the power of his oratory. But this speech is different, White House officials said.

Determined not to simply recite a history of the last eight years, Obama directed his team to craft an address that would feel “bigger than politics” and speak to all Americans — including those who voted for Trump.

His chief speechwriter, Cody Keenan, started writing it last month while Obama was vacationing in Hawaii, handing him the first draft on the flight home. By late Monday Obama was immersed in a fourth draft, with Keenan expected to stay at the White House all night to help perfect Obama’s final message.

Ahead of his speech, Obama acknowledged that the chaos of Washington makes it easy to lose sight of the role American citizens play in democracy. He said that while he leaves office with his work unfinished, he believes his administration made the U.S. “a stronger place for the generations that will follow ours.”

Seeking inspiration, Obama’s speechwriters spent weeks poring over Obama’s other momentous speeches, including his 2004 keynote at the Democratic National Convention and his 2008 speech after losing the New Hampshire primary to Hillary Clinton. They also revisited his 2015 address in Selma, Alabama, that both honored America’s exceptionalism and acknowledged its painful history on civil rights.

Former aides were brought back to consult on the speech, including advisers David Axelrod and Robert Gibbs, and former speechwriter Jon Favreau, said the officials, who requested anonymity because they were not authorized to publicly discuss the private discussions.

Vice President Joe Biden and his wife were also traveling to Chicago for the speech at McCormick Place, a sprawling convention center along Lake Michigan. For Obama, it will be his final trip aboard Air Force One as president, though he’ll use the plane to depart Washington for an unspecified destination next week just after Trump is inaugurated.

In his hometown of Chicago, the prospect of witnessing Obama’s last presidential address brought thousands out in single-digit temperatures over the weekend in hopes of securing tickets. They showed up well before sunrise and waited in lines that stretched for blocks.