US president Barack Obama has led civil rights pioneers in a ceremony marking the 50th anniversary of the March on Washington, where Martin Luther King’s “I Have a Dream” speech roused the 250,000 people who rallied there for racial equality.
Large crowds gathered at the Lincoln Memorial in the capital to hear the first black US president speak.
"They came by the thousands, from every corner of our country: men and women, young and old, blacks who longed for freedom and whites who could no longer accept freedom for themselves while witnessing the subjugation of others," he said.
Referring to the turbulent 1960s in America, Mr Obama said: “There were couples in love who couldn’t marry. Soldiers who fought for freedom abroad, but couldn’t find any at home.
“America changed for you and for me.”
But he pointed to the nation’s economic disparities as evidence that Dr King’s hopes remain unfulfilled.
The name of that original march was the March on Washington for Jobs and Freedom.
Mr Obama has said Dr King is one of two people he admires “more than anybody in American history,” the other being Abraham Lincoln.
Thousands of people were in attendance in wet weather.
Oprah Winfrey also spoke, saying Martin Luther King Jr forced the US ``to wake up, look at itself and eventually change''.
The TV personality said the civil rights leader’s lessons continue to inspire people all over the world.
Winfrey said Dr King recognised that Americans shared the same dreams and that their hopes were not different based on race.
She said King was right when he said all Americans’ destinies are intertwined and would rise or fall based on how people treat their neighbours.
Winfrey said she asked her mother as a nine-year-old girl why her family was not there for the march. Winfrey said it took 50 years, but she finally arrived on the steps of the Lincoln Memorial to mark the anniversary of King’s march.
Former US president Bill Clinton said the anniversary marks ``one of the most important days in American history''.
Mr Clinton said that march, and that speech, “changed America… opened minds and melted hearts … and moved millions”.
Mr Clinton added that racial inequalities remain.
But he said it is time to stop complaining and instead get to work – for better education opportunities for all children and implementing health care for all.
He said “we must push open those stubborn gates” that are holding America back.