From "Confessions of a Nonpolitical Man" by Sven Birkets in the July-August issue of the Utne Reader:

A few years ago, on Martin Luther King Day, I was interviewed on CNN along with Rosa Parks. "[She] was the woman who wouldn't go to the back of the bus," said the host. "That set in motion the yearlong bus boycott in Montgomery. It earned [her] the title of `mother of the civil rights movement.' "

The host's description -- the standard rendition of the story -- stripped the boycott of its context. Before refusing to give up her seat to a white person, Parks had spent 12 years helping to lead the local NAACP chapter. The summer before, she had attended a 10-day training session at the Highlander Center, Tennessee's labor and civil rights organizing school, where she'd met older activists and discussed the Supreme Court's decision banning "separate but equal" schools. Parks had become familiar with previous challenges to segregation: another Montgomery bus boycott, 50 years earlier; a bus boycott in Baton Rouge two years before Parks was arrested; and an NAACP dilemma the previous spring, when a young Montgomery woman had also refused to move to the back of the bus. The NAACP had considered a legal challenge but decided that the unmarried, pregnant woman would make a poor symbol for a campaign.

In short, Parks didn't make a spur-of-the-moment decision. She was part of a movement for change at a time when success was far from certain.