On February 1, 1960, four black students from North Carolina Agricultural and Technical College in Greensboro, North Carolina, walked into a Woolworth’s store and quietly sat down at the lunch counter. This seemingly mundane, everyday act sent shock waves through Greensboro, through North Carolina, and through the nation. The counter at which these four young men sat was for whites only.

This simple act was like a stone thrown into a still pond. It sent out ripples across the nation that stirred people to take...