During the summer of 1943, racial clashes broke out in several cities throughout the United States, including Beaumont, TX, Mobile, AL and Los Angeles. The worst of the wartime race riots occurred on June 20 in Detroit, MI. The nation's fourth largest city during the war, Detroit was overcrowded and tense, and the governor order martial law. So many race riots erupted during the war, that in October of 1943, the American Civil Liberties Union published a pamphlet detailing how to prevent race riots in your hometown.