This morning tens of thousands of Americans are beginning to descend on the National Mall, exactly 50 years after the celebrated March on Washington.
As people recall the epic events of that summer of 1963, and of course celebrate the most memorable speech of the 20th Century, they are also engaged in some soul searching.
How far has America come in realising the dream of Martin Luther King? Why is racial harmony and economic equality so elusive even now?
These are questions I too have asked since first moving to America 12 years ago. Why is the legacy of slavery, of segregation, of discrimination so stubborn and poisonous?
Two events helped define the civil rights movement: the March on Washington in August 1963, which is being remembered today, and two years later the protest walk from Selma to Montgomery in Alabama.
That protest march was viciously attacked by local police as the civil rights activists walked across the bridge at Selma. Beamed around America - breaking TV news coverage was in its infancy - the images shocked millions of white Americans.
So I returned to Selma last week and retraced the steps of those activists. What would I find in 2013 along this historic route through the cotton fields of the Deep South? A sense of progress and of optimism or a continuing anger at entrenched discrimination?
We drove those 50 miles from Selma to Montgomery, Alabama's state capital. We found poverty and wealth, signs of hope and much anger, resilience and despair.
We spoke to a woman who still sees racism embedded in America "from New York to California." We met a former Mayor who says Selma is still segregated - not by law but in practice. We encountered a woman who said it is whites who now face discrimination.
We even heard from a civil rights activist who claimed that America is currently going backwards in its tortuous journey towards equal rights.
Overall, it was a glimpse of how far America has travelled in 50 years, and how far this country still has to go.