After the events of the movie, the real Monty Stratton went on to be a coach for the Chicago White Sox for a couple of years before going back to his home town of Greenville, TX to start his own farm team. In 1946, he shocked the world when he took the mound once again, this time in the minor leagues, and he posted an 18-8 record for that season.
Although Monty Stratton was a real baseball player who continued to play baseball after having a right-leg, above-knee amputation, much of the story was fictionalized for this film. For instance, in the hunting accident, the real Monty Stratton shot himself with a pistol, rather than with a rifle. Also, the game in which the real Monty Stratton returned to baseball after his amputation was not an All-Star game, as in the movie, but rather a 1939 charity game between the White Sox and the Cubs (the proceeds of which went to Stratton).
Monty Stratton played for the Chicago White Sox from 1934-38 and compiled a 36-23 won/loss record and 3.71 Earned Run Average with 196 strikeouts. He was a better than average hitter (for a pitcher) with a .224 (43/192) batting average, hitting four home runs and 24 runs batted in.
Producers originally considered Donna Reed for the role of Ethel Stratton, but replaced her with June Allyson after signing James Stewart, since Stewart's and Reed's previous co-starring venture, It's a Wonderful Life (1946), had been a disappointment at the box office. This was, of course, before television had made the Capra film a holiday favorite.
The song "You are my lucky star" plays in the background of the double date scene at the beginning of the movie, three years after Sammy Davis Jr. recorded it (1946) and three years before Gene Kelly and Debbie Reynolds popularized it in Singing in the Rain (1952).