Marcus Garvey's Universal Negro Improvement Association was the largest Black mass movement in American history — millions of members, the Black Star Line, and a program of African redemption that terrified the young J. Edgar Hoover, whose Bureau hired its first Black agents specifically to infiltrate it. Unable to find sedition, the government prosecuted Garvey in 1923 for mail fraud over a Black Star Line brochure — a case so thin it centered on a single empty envelope.

Sentenced to five years, Garvey entered Atlanta Penitentiary in 1925; President Coolidge commuted the sentence in 1927 on condition of deportation, and the movement's founder was shipped to Jamaica, never to return. The case established the template later perfected under COINTELPRO: when a Black movement cannot be defeated politically, imprison its leader on whatever charge can be made to stick.