The day before the inauguration of its first black president, America has marked the 80th anniversary of slain African-American civil rights leader Martin Luther King Jr.
Speaking in Washington, Obama highlighted the significance and how far America has travelled.
“Tomorrow, we will come together as one people on the same Mall where Dr. King's dream echoes still,” Obama said.
Martin Luther King Jr delivered his famous speech ‘I have a dream’ over 45 years ago, in August 1963.
Mr Obama has frequently referenced Dr King, and in his pre-inauguration speeches has been calling on Americans to renew the promise of the nation.
The day is also called Service Day, when Americans voluntarily help people in need.