nomic rights of African Americans. At the march, several popular singers of the time, including Mahalia Jackson and Marian Anderson, performed and many of the movement's leaders gave speeches. The most notable speech came from the final speaker, Dr. Martin Luther King Jr., standing in front of the Lincoln Memorial, as he delivered his historic "I Have a Dream" speech in which he called for an end to legalized racism and racial segregation. The march was organized by Bayard Rustin and A. Philip Randolph, 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. The march is credited with helping to pass the Civil Rights Act of 1964. It preceded the Selma Voting Rights Movement, when national media coverage contribute