A look back at Barack Obama's inauguration as Donald Trump's approaches.

America is four days away from the inauguration of its 45th president, and no one’s quite sure what to expect.

Protests have been planned, political and celebrity boycotts have been widely publicised, and the president-elect, Donald Trump, has vowed to make the somewhat stripped-down affair all about “the people” — whatever that means.

The nervous build up to January 20, 2017, couldn’t be more starkly different from the global euphoria felt surrounding the same day eight years ago, when Barack Obama was sworn in for his first term as President of the United States.

Obama’s inauguration was a star-studded affair, which holds the attendance record for any event in Washington D.C. to date, while Trump is struggling to get even minor celebrities in his corner.

Performances from Beyoncé, Aretha Franklin, U2 and Bruce Springsteen peppered the historic day, among an impressive raft of others.

By comparison, Trump has been turned down by everyone from Charlotte Church to Elton John.

Despite the winter cold, nearly two million Americans gathered to watch Obama, 55, and his vice-president Joe Biden sworn in, while the broadcast was streamed across the world.

The Democrat's wife, Michelle, held the bible on which he took the Oath of Affirmation, while his daughters, Malia and Sasha, stood smiling by her side.

Obama entered office promising "Hope" and greater accountability in the wake of the global financial crisis; America's first black president.

"That we are in the midst of crisis is now well understood.  Our nation is at war against a far-reaching network of violence and hatred.  Our economy is badly weakened, a consequence of greed and irresponsibility on the part of some, but also our collective failure to make hard choices and prepare the nation for a new age," he told the crowd, who hung on his every word.

"Today I say to you that the challenges we face are real.  They are serious and they are many.  They will not be met easily or in a short span of time. But know this America:  They will be met."

Watch the inauguration speech in full via the New York Times (post continues after video):

Many were brought to tears by the historic pledge, though how many of its goals were or will be met remains to be seen, especially with Trump pushing to wind back many of his predecessor's hard won reforms.

Last week, Obama wrapped up his tenure with another powerful speech, in which he implored his supporters to keep fighting.

“Show up. Dive in. Stay at it," he said.

It's not yet known what will happen over the next four days — let alone the next for years — but it does seem likely Trump's first day as President will likely be a more sombre affair for many.

If you missed it, The Mamamia Out Loud team released a special post-election episode. Listen below: