Even as racial barriers have tumbled and the nation has grown wealthier and better educated, the economic disparities separating Blacks and Whites remain as wide as they were when marchers assembled on the Mall in 1963. When it comes to household income and wealth, the gaps between Blacks and Whites have widened.

On other measures, the gaps are roughly the same as they were four decades ago. The poverty rate for Blacks, for instance, continues to be about three times that of Whites.

“The relative position of Blacks has not changed economically since the march,” said William Darity Jr., a professor of public policy, economics and African American studies at Duke University. “Certainly, poverty has declined for everybody, but it has declined in a way that the proportion of Blacks to Whites who are poor is about the same as it was 50 years ago.”