US President Barack Obama, Vice President Joe Biden have participated in community service projects to commemorate slain civil rights leader Martin Luther King.
"Today, we celebrate the legacy of Dr. Martin Luther King, Jr. And we should honor that legacy by acting as drum majors for service and lifting up those less fortunate -- not just today, but every day," Obama said in a statement.
"All of us can find a way to give back to our communities, to gain new skills, and to pull together, even when times are hard. That's what Dr. King believed in, and that's what will make our country stronger."
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The first family participated in a service event sponsored by Big Brothers Big Sisters and Greater DC Cares at the Browne Education Campus in Washington, the White House said.
The Bidens meanwhile participated in an event at Girard College in Philadelphia.
Other senior Obama administration officials including Agriculture Secretary Tom Vilsack and Education Secretary Arne Duncan also took part in community service events.
King was shot dead in Memphis, Tennessee in April 1968.
A memorial dedicated to King and his message of non-violence and justice is now open to the public on the Mall in Washington. The formal inauguration ceremony took place in October.
The statue of the 1964 Nobel peace laureate faces out across the Tidal Basin, towards the Jefferson Memorial.
It is located near the Lincoln Memorial, where the black pastor gave his famous "I Have a Dream" speech on August 28, 1963, helping to galvanize a movement.
But after complaints that one of the key quotes inscribed on the side of the statue paraphrases King's words incorrectly, Interior Secretary Ken Salazar has asked the National Park Service to rectify the error.
The inscription reads, "I was a drum major for justice, peace and righteousness."
Research by a columnist for the Washington Post showed the quote was taken from one of King's speeches in which he actually said, "If you want to say I was a drum major, say I was..."
