As the minor league team bus approaches the rural gas station, a caption says "Interstate 24". The Interstate system started in 1956. The road is most likely US Highway 24, which runs east-west through Kansas City.
The first establishing shot outside Branch Rickey's office, the Mechanics Bank Building, shows an elevated subway passing by. While there was a subway line at that location, it ceased operation in 1940, and was demolished soon after.
After a deliberate pitch hits Jackie Robinson in the forehead, stitches and Steri-strips keep the wound closed. Micropore tape, the precursor to Steri-strips, was invented in 1959. The original Steri-strips were first used in 1962. The Steri-strips used in the movie first appeared in the early 1990s.
During Rachel's introductory shot, the camera slowly tracks toward her as she answers the phone in the hallway. A modern-day air conditioning return vent is clearly visible on the left wall. Carrier developed the first home air conditioner in 1928, but it was very rare in homes until the 1950s.
New York City police officers at Ebbets Field have silver nameplates below their badges. Nameplates were added to the NYPD's uniform regulations in the early 1970s, and they were black with white lettering for a decade.
When Burt Shotton introduces himself to the Dodgers as the new manager, the team is wearing their gray "road" uniforms and standing in the visiting clubhouse of the Polo Grounds, the Giants' home ballpark. He asks who the Dodgers are playing, and someone replies "The Giants," which Shotton should already know.
When the Baseball Commissioner tells Branch Rickey that he must suspend Leo Durocher, he is reading a newspaper article about Durocher's "Love Nest." A sidebar article on the same page mentions Durocher's mother commenting about his suspension, which hadn't happened yet.
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.
When Jackie and Rachel are dropped off at the house in Daytona Beach, Wendell tells them they will stay 'till the end of the week, then go to Sanford "only 45 minutes away". To travel from Daytona Beach to Sanford in 45 minutes, they would've had to average 80 mph on roads considered 'back roads' today.
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."
The game on September 17, which Jackie Robinson hits a home run off of Pirates pitcher Fritz Ostermueller to help the Dodgers clinch the pennant, was not the actual day the Dodgers clinched the pennant. The National League standings at the end of play that day had the Dodgers with a record of 91-54, while the second place Cardinals had a record of 80-62. With 154 games in a season, it was still possible for the Cardinals to win the pennant with a record of 92-62, with the Dodgers finishing in second place with a record of 91-63.
Red Barber is shown broadcasting road games in Pittsburgh and Cincinnati. However, in 1947 he did not travel with the team but instead recreated games at home in a studio based on data sent by wire via Western Union. Live Dodger broadcasts of away games didn't begin until 1948.
When he arrives at spring training for the Montreal Royals, Wendell Smith introduces himself to Robinson. In real life, the two had already met in 1945, when Smith had arranged a special try-out for Jackie Robinson with the Boston Red Sox.
In 1947 after signing Hank Greenberg, the left field fence in Forbes Field (PGH) was shortened to allow for more homers and was labelled "Greenberg Gardens". The bullpens were there also. When the film shows Jackie homering off Ostermueller, the old fence and layout are shown.
The radio broadcast booth in Ebbets Field is lettered with WMGM. However, the radio station at that time used the call letters WHN. The call letters of the station weren't changed until the following year.
Halfway through the movie, when Wendell and Jackie are driving in New York, they are going West on 34th street. You can see the Empire State Building and the New Yorker on the same side of the street (south side) even though the New Yorker is across the street.
Wendell and other characters type on manual typewriters throughout the film. Every sentence and every name begins with a capital letter, yet none of the characters ever presses the 'shift' key (very noticeable on a manual typewriter).
When Pee Wee Reese shows the threatening letter to Mr. Rickey, the door behind Pee Wee says "Private" backward because the lettering is on the other side of the window. The "R" in Private is facing the right way, when it should be backward.