The march was organised by A. Philip Randolph and Bayard Rustin, who built an alliance of civil rights, labor, and religious organizations that came together under the banner of "jobs and freedom." Estimates of the number of participants varied from 200,000 to 300,000, but the most widely cited estimate is 250,000 people. Observers estimated that 75–80% of the marchers were black. The march was one of the largest political rallies for human rights in United States history. Walter Reuther, president of the United Auto Workers, was the most integral and highest-ranking white organizer of the march.