This photograph was taken on August 28, 1963, during the March on Washington for Jobs and Freedom. The march was organized by leaders of civil rights organizations, including leaders of the NAACP, the Congress of Racial Equality, and the Student Nonviolent Coordinating Committee, as well as Martin Luther King Jr., president of the Southern Christian Leadership Conference. Historians estimate that about 250,000 people participated in the event. Of these, about three-fourths were African American and one-fourth were white. Most of the marchers carried premade signs provided by the organizers.