Thousands are gathering in the US capital to mark 50 years since Martin Luther King's famous "I have a dream" speech on civil rights.
Today's civil rights activists came to Washington with concerns that include jobs, voting rights and gun violence. They are marching to the Lincoln Memorial and a new monument, the Martin Luther King Jr Memorial.
Saturday's event is being led by the Rev Al Sharpton and King's son Martin Luther King III.
It comes a few days before the actual anniversary of the original march on 28 August 1963.
King, who was assassinated in 1968, led about 250,000 people to the Lincoln Memorial on the National Mall and delivered his famous speech from its steps.
"I have a dream that my four little children will one day live in a nation where they will not be judged by the colour of their skin but by the content of their character." he said, in one of the most celebrated pieces of American oratory.
Barack Obama, the first black US president, is due to commemorate the event on the anniversary itself with a speech from the same spot.
He will be joined by former Presidents Bill Clinton and Jimmy Carter, while churches and groups have been asked to ring bells at 15:00 (19:00 GMT) on Wednesday to mark the exact time King spoke.