Rosa Parks, a seamstress in Montgomery, Alabama, refuses to obey the order of bus driver James F. Blake to give up her seat to a white passenger. Her case will lead to the Montgomery Bus Boycott and a formal legal challenge of the racial segregation laws in Alabama.
Rosa Parks actually sits in the rear section of the bus reserved for "colored" riders, but because of the large number of white riders the bus driver moves the segregation line backwards and Parks refuses to move to make room for whites.
The Montgomery Bus Boycott will create significant hardship for the black residents of Montgomery, but it also creates significant hardship for the bus company. The city, however, refuses to repeal the segregation law until after the U.S. Supreme Court declares it unconstitutional.