Rosa Parks: Change the world in a single bus ride? Rosa Parks did. Parks wasn’t the first oppressed American to refuse to give up her seat for a white passenger on public transit, but she was the one who sparked the Montgomery Bus Boycott.
Roger Boisjoly. In 1986, he warned his engineer colleagues and NASA that Space Shuttle Challenger was not ready to fly and that engineering issues would mean certain disaster. No one listened. He was, unfortunately, right. He said "Everybody has the responsibility to do what they get paid for and that is to stand up for what they know is right and what their profession demands of them and that’s all I did. And I’d do it again."