On December 1, 1955, Rosa Parks, a black seamstress, was arrested when she refused to listen to a Montgomery bus driver's order to give her seat up for a boarding white passenger as required by city law. There were many laws in the South during that time made to separate the races.
The African Americans in Montgomery's were outraged about Rosa Parks' arrest. In protest, many people chose to boycott against the city's bus line -- the people chose to walk rather than use the buses.
The Boycott ended in December 1956, over a year after it began, when the U.S. Supreme Court ordered the desegregation of buses in Montgomery.