Obama, who was officially sworn in Sunday in a private ceremony at the White House, will speak before an expected crowd of 800,000 on the National Mall and millions more watching at home.
But while the inauguration will be a flag-waving moment of unity for many Americans, it is likely to be a fleeting one, just as similar moments at other points during Obama's first term -- from mass shootings and natural disasters to the killing of bin Laden -- have been.
This week alone will see partisan passions flare when outgoing Secretary of State Hillary Clinton testifies on Capitol Hill over the terrorist attack in Benghazi, Libya. The battle over gun-control legislation heats up as bills are brought to the congressional floor. And Senators of both parties are girding for a fight with the White House over Defense Secretary nominee Chuck Hagel, whose confirmation hearings start on Jan. 31.
Obama has been working on his inaugural address since mid-December, officials said, working through drafts of the text on yellow legal pads that he's been spotted carrying through the West Wing. He also hosted a dinner with presidential historians at the White House last week, looking for insights on how to make his speech memorable and impactful.
In a video message to his supporters reflecting on the moment, Obama said two historical figures would be especially on his mind today: Dr. Martin Luther King, Jr., and President Abraham Lincoln.
"Their actions, the movements they represented are the only reason it's possible for me to be inaugurated," Obama said. "It's also a reminder for me that this country has gone through very tough times before, but we always come out on the other side."
For the ceremonial oath-taking, Obama will place his left hand on the stacked personal Bibles of Lincoln and King.