historic moment until now. branch rickey s decision to hire jackie robinson as the first african-american baseball player opened doors that changed sports and politics forever. and the details are etched in the memory of ken burns who did the definitive 18 and a half hour pbs documentary on baseball. one of the finest moments in all of american history, not just sports history, but american history, when on april 15th, 1947, a black man wearing the number 42 trotted out to first base. reporter: we ve learned a detail about this decision that until now was not known by jackie robinson s widow, branch rickey s grandson or even ken burns. you ve never heard this story? no. reporter: it turns out before signing the contract, rickey slipped into this brooklyn church. the executive huddled with the pastor whose daughter in law is speaking with us about it for the first time. he started pacing. he wore a groove in the carpet.