How did A. Philip Randolph successfully contribute to the Civil Rights Movement?

A. Philip Randolph's main contribution to the civil rights movement was his linkage of the struggle for racial equality with social and economic equality for workers. Randolph differed from many civil rights campaigners in that he strongly believed that the black working class, occupying as it did the lowest rungs of society, was the main vehicle for social change in America.
Randolph is most famous for his organization and leadership of the Brotherhood of Sleeping Car Porters (BSCP), the first predominantly African American labor union. Pay and conditions for porters were poor, and in his new role as President of the BSCP Randolph campaigned tirelessly for an improvement in his members' wages and working conditions. Eventually, Randolph's ceaseless efforts bore fruit when the Roosevelt Administration amended the Railway Labor Act of 1934 to ensure that porters were finally granted employment rights under federal labor law. Over the course of the following years, BSCP membership soared as railway porters saw their wages and conditions improve considerably.
During World War II, Randolph used his position as a prominent labor leader to campaign against discrimination towards African Americans in the military, defense industries, and labor unions themselves. Once again, Randolph's campaigning and lobbying paid off as FDR issued Executive Order 8802, banning discrimination in defense industries. Randolph was also instrumental in President Truman's abolition of segregation in the United States armed forces in 1948.
During the heyday of the Civil Rights Movement in the 1960s, Randolph was once again at the forefront of events. He was involved in the famous March on Washington in 1963, and he joined with Martin Luther King in organizing peaceful protests against segregation and discrimination in the South. Randolph's lifelong contribution to the cause of civil rights was acknowledged by President Johnson when Randolph was awarded the Presidential Medal of Freedom in 1964, the same year that the Civil Rights Act was finally passed.