Final answer:
Phil Hoose was surprised to learn about Claudette Colvin's early act of resistance against bus segregation prior to Rosa Parks, whose arrest had sparked significant action in the civil rights movement.
Step-by-step explanation:
Author Phil Hoose was surprised to learn about Claudette Colvin because she was a precursor to Rosa Parks in the fight against segregation on Montgomery buses. Despite Colvin's courageous act of refusing to give up her seat to a white person months before Parks' more famous protest, her story was lesser-known. The local black community initially supported her, but when it was discovered she was pregnant and unmarried, their support waned. In contrast, when Rosa Parks, a respected community member, was arrested, Montgomery NAACP leaders seized the moment to spark wider civil rights action. The significant difference in the community's reaction to Colvin versus Parks is illustrative of the strategic choices made by civil rights leaders to galvanize support and effect change.