The four original participants in the Woolworth's lunch counter sit-in walk down the street after leaving the lunch counter on Feb. 1, 1960. The Woolworth's sit-ins continued for months and inspired sit-ins across the country, which helped change public opinion and led to the end of segregation.
Jack Moebes/Corbis
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Bob Karch is the chairman and a professor in the Department of Health and Fitness at American University. Here, he helps cross-country champion Steve Hallinan check his heart rate while cross-training on the bike.
Allison Aubrey/NPR
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