Slavery and the National Anthem: The Surprising History Behind Colin Kaepernick's Protest

"I cannot stand and sing the anthem. I cannot salute the flag. I know that I am a black man in a white world."

That's not Colin Kaepernick, the San Francisco 49ers quarterback whose refusal to stand during the national anthem has invited criticism from all corners of the sports world. 

That's Jackie Robinson, beloved baseball pioneer and civil rights activist, writing in his 1972 autobiography, "I Never Had It Made." 

After Kaepernick was spotted sitting during the anthem preceding last Friday's NFL preseason game, the struggling quarterback said he would not stand "to show pride in a flag for a country that oppresses black people and people of color."