How did a cancelled Civil Rights protest change federal law?

Before the US officially entered World War II in 1941, civil rights activist Asa Philip Randolph called for a March on Washington to demand an end to racial discrimination in the defense industries and in the military. Concerned with protecting America's image overseas if tens of thousands of demonstrators called attention to racial inequality in the US, President Franklin D. Roosevelt partially conceded to Randolph's demands. The President signed Executive Act 8802, which ended discrimination in the defense industries, and Randolph cancelled the march. Other Mall protests publicized inequality, but they had failed to produce immediate, concrete results like this canceled march.

How did a cancelled Civil Rights protest change federal law?

Discriminatory hiring policies prevented African Americans from applying for hundreds of thousands of new jobs created in defense-related industries during World War II. Few African Americans served in the US Armed Forces and government service, and fewer benefited from federal job training programs. Asa Philip Randolph, a well-respected union leader, urged President Franklin Roosevelt to change government policy and to give African Americans equal access to these jobs.

First Lady Eleanor Roosevelt organized a meeting for Randolph and other African American leaders to meet with the President in September 1940. During her career as First Lady, Eleanor used her position to fight for equality for African Americans and all citizens. After this first meeting, President Roosevelt refused to integrate the miliary or to lift restrictions on hiring. More concerned about US involvement in World War II, the President saw changing federal employment law as too controversial while politicians and citizens debated about entering a war.

With the President's refusal, Randolph began planning a march on Washington to ask for equal access to defense jobs and integration of the military. Using African American newspapers and public speeches, he publicized the march as a way to  exert pressure on the president. Randolph called for thousands to join the march and demand government action using the following slogan: "We loyal Americans demand the right to work and fight for our country."

The White House recognized the impact of tens of thousands of demonstrators on the National Mall. Two years earlier, more than 75,000 people had assembled to hear African American contralto Marian Anderson sing at the Lincoln Memorial after the Daughters of the American Revolution denied her permission to perform in segregated Constitution Hall. Other nations already criticized American racial policies, and the White House feared Randolph’s planned demonstration would further tarnish the country’s reputation abroad and create a backlash at home. As momentum grew in support of the March, Roosevelt scheduled a second meeting with Randolph.

Pressured by Randolph, the First Lady, and the possibility of 100,000 African Americans marching in Washington, President Roosevelt issued Executive Order 8802 on June 25, 1941. The Order prohibited discrimination in defense industries and established the Fair Employment Practices Committee (FEPC) to monitor hiring practices. Executive Order 8802 was the first major federal government response to racial inequality since Reconstruction. A separate executive order in 1948 desegregated the US Armed Forces. The march that never happened became the first planned demonstration on the National Mall to result in concrete change in government policy.