During World War II, approximately 909,000 African-Americans enlisted in the military, and about 500,000 of them were stationed overseas [source: Harris]. After the war, President Harry S. Truman recognized how hypocritical it was to have a segregated military while he'd been trying to promote democracy and acceptance overseas [source: Geselbracht].
The Supreme Court, meanwhile, was making some milestone civil rights decisions throughout the 1940s. In 1944, the court banned the all-white political primaries that were occurring in the South and struck down segregation in interstate bus travel two years later. Many Southerners in the House of Representatives and the Senate were still effectively blocking anti-lynching legislation after the outbreak of race riots.
In November 1947, civil rights leaders A. Philip Randolph and Grant Reynolds formed the Committee Against Jim Crow in Military Service and Training, which originally targeted Congress for action to desegregate the military. When they found this route fruitless, they turned to Truman. If he issued an executive order on the issue, it wouldn't be subject to a legislative vote. This was a smart move because in addition to Truman's sympathies toward the cause, he was coming up on an election year. Rooting out discrimination in the military could help him secure the African-American vote, which made up about 10 percent of the electorate.
To give Truman that final push, Randolph and Reynolds sent a letter to Truman, threatening that the African-American youth would boycott the draft if he didn't sign an executive order to end segregation in the military. On July 26, 1948, one month after receiving this letter, Truman issued Executive Order 9981, which stated, "there shall be equality of treatment and opportunity for all persons in the armed forces without regard to race, color, religion, or national origin" [source: Truman Library]. It also created a committee to investigate the state of affairs and rules of the military so that it could report back to the president with suggestions on how to enforce integration.
The military didn't achieve racial integration overnight. Opponents in Congress were able to delay the effort by falsely interpreting Truman's language. Truman wrote that the military needed to achieve integration as fast as possible, "without impairing efficiency or morale." Taking liberties with Truman's language, Secretary of the Army Kenneth Royall hampered desegregation by prolonging the implementation of integration procedures [source: Geselbracht].
During the Korean War in the early 1950s, much of the military had been racially integrated. By the end of the war, about 10 percent of African-Americans were still serving in segregated units, which were abolished completely in 1954 [source: Harris].