Mrs. Rosa Parks altered the negro progress in Montgomery, Alabama, 1955, by the bus boycott she unwillingly began. National Archives record ID: 306-PSD-65-1882 (Box 93).
Source: Ebony Magazine, now Public Domain
Several days before she famously, on December 1, 1955, refused to give up her seat to a white person, she attended an NAACP meeting that discussed the murders of Emmett Till, Lamar Smith and George W. Lee. At age 42, she had had her fill of racial discrimination. In her own words, from her autobiography, My Story:
That's definitely my kind of uppity.
Rosa Parks sits in the front of a bus in Montgomery, Alabama, in 1956 immediately after the U.S. Supreme Court ruled segregation illegal on the city's bus system. Behind Parks is Nicholas C. Chriss, a UPI reporter covering the event.
United Press International photo.
(From Wikipedia, stated as Fair Use)