The Montgomery bus boycott began on December 6, 1955, prompted by the arrest five days earlier of Rosa Parks. The boycotters were led by Martin Luther King Jr. They walked and carpooled to protest segregation in public transportation. They faced harassment and violence from white police and residents. In November 1956, the Supreme Court ruled in Gayle et al. v. Browser that segregation of the city’s buses was unconstitutional. African Americans returned to Montgomery’s buses on December 21, 1956.