Parks was a civil rights activist before her arrest

Parks' campaign for Black Americans' equal rights did not begin with her disastrous arrest. Parks was a long-time member of the National Association for the Advancement of Colored People's (NAACP) Montgomery chapter, which she joined in 1943. She was the secretary of the local NAACP branch at the time of her arrest, and she had attended a social and economic justice course at Tennessee's Highlander Folk School the previous summer.

Her responsibilities included going around the state and interviewing discrimination victims and lynching witnesses. Parks served as an assistant to U.S. Representative John Conyers after moving from Alabama to Detroit, where she assisted in the search for housing for the homeless. Her political activism lasted the duration of the boycott and into her later years.

Parks had no intention of starting a movement, yet she did so shortly after her imprisonment. Civil rights organizations exploited her peaceful demonstration to draw national attention to the Deep South's unconstitutional segregation laws. The Montgomery bus boycott began mere days after her imprisonment, and the city's segregated buses were declared illegal by the Supreme Court less than a year later. Many historians consider Parks' arrest and the bus boycott to be the catalysts for the campaign that resulted in federal civil rights legislation in the 1960s.