Factual error: Although the movie is set in 1962, when Rodriguez jumps the fence of the junkyard, a red door from a '73-88 GM pickup can be seen in the background.
Factual error: At the beginning of the carnival scene, the Gravitron ride is in the far background. This movie is set in 1962, and the Gravitron was not introduced until 1983.
Factual error: In his voiceover narration, Smalls says that Babe Ruth's "called shot" was made at Yankee Stadium in the bottom of the ninth inning in game 3 of the 1932 World Series. That play actually occurred in the top of the fifth inning at Wrigley Field. It's not just a character mistake; the event is too famous for him not to have heard or read about it growing up, especially since his stepfather is a Yankees fan.
Factual error: When Franklin grabs the ball and hurdles the fence, in the next shot we see the dog (a tiny bulldog) also jump the fence and chase him. No dog that small would reasonably or realistically jump a 12 ft fence, even with a very long-running start. It would be physically impossible. This was purely for comical purposes, nothing else.
Factual error: The film takes place in the summer of 1962. The scene where the boys go to the local pool to swim, in actuality this is during the civil rights movement when racial injustice against African Americans was at its peak - they would have never allowed a young black child to swim in an all white pool during this year and time.