Pee Wee Reese's line that someday all Dodger players might be wearing the number 42 was actually said by Dodgers outfielder Gene Hermanski in 1951. Brian Helgeland liked the quote so much, he had Reese say it because he is a central character. Since 2004, every April 15th has been "Jackie Robinson Day" in Major League baseball, and every player wears number 42. Robinson's first day in the Major Leagues was April 15, 1947.
The last scene of the movie takes place at Forbes Field in Pittsburgh. The stadium was not used after 1970 when the Pirates moved to Three Rivers Stadium. Within this last scene, as Jackie rounds the bases for his home run a shot of the Cathedral of Learning is shown. The Cathedral of Learning is the famous building for the University of Pittsburgh. Forbes Field was located right next to the university in real life. After Forbes Field was torn down, the university kept home plate at the field in its exact location. The home plate of Forbes Field is encased in the ground at the same location as it was in the movie in William Posvar Hall at the University of Pittsburgh.
Alan Tudyk claimed that he and Chadwick Boseman deliberately avoided fraternizing while filming their scenes together, to better convey the animosity between Jackie Robinson and Ben Chapman.
The Home Run in the 4th inning that put the Brooklyn Dodgers ahead of Pittsburgh and lead to the 1947 pennant came in the following sequence: Ball 1, Ball 2, Foul, Foul, Home Run. The film shows a 3-0 count with Jackie asking for "something he can hit."
Halfway through the movie, when Wendell and Jackie are driving in New York, they are going west on 34th street. The Empire State Building and the New Yorker are on the same side of the street. In real life, the New Yorker is across the street.
In the game against the Phillies, when Philly Manager Chapman baits Jackie, Robinson steals second, goes to third on an error, and scores on a single by Gene Hermanski, who bats with his right hand. In real life, Hermanski was a left-handed batter.