Jackie Robinson refuses to move to the back of a bus, leading to his court-martial.

Jack Roosevelt Robinson was an American professional baseball player who became the first Black American to play in Major League Baseball (MLB) in the modern era. Robinson broke the color line when he started at first base for the Brooklyn Dodgers on April 15, 1947. The Dodgers signing Robinson heralded the end of racial segregation in professional baseball, which had relegated black players to the Negro leagues since the 1880s.

A court-martial is a military court or a trial conducted in such a court. A court-martial is empowered to determine the guilt of members of the armed forces subject to military law, and, if the defendant is found guilty, to decide upon punishment. In addition, courts-martial may be used to try prisoners of war for war crimes. The Geneva Conventions require that POWs who are on trial for war crimes be subject to the same procedures as would be the holding military's own forces. Finally, courts-martial can be convened for other purposes, such as dealing with violations of martial law, and can involve civilian defendants.