Jackie Robinson broke baseball's color barrier 75 years ago
Crossing Baseball's Color Line - Jackie Robinson: Breaking the Color Barrier
Baseball color line - Wikipedia
The History of Segregation in Baseball - The Leadership and Legacy of Jackie Robinson
Jackie Robinson: A Legacy of Activism - The American Prospect
The Man Who Broke Baseball's Color Line Before Jackie Robinson - Big Think
The Drawing of the Color Line, 1867, by John Thorn
Baseball, Race Relations and Jackie Robinson, Classroom Materials at the Library of Congress
Jackie Robinson broke baseball's color barrier 75 years ago
Crossing the Color Barrier: Jackie Robinson and the Men Who Integrated Major League Baseball - LA84 Foundation