The Green Book, a travel guide for black motorists, was invaluable for African Americans traveling through segregated America. Published for 3 decades, from the mid 1930s to the mid 1960s, it was indispensable for black travelers. Because black travelers couldn't eat, sleep or buy gas at most white-owned businesses, they needed a list of safe businesses for them. It took courage to fight back against the institutionalized racism and Overground Railroad relates the tales of those who did just that.