Factual error: Although quite typical for biopics of this era, certain aspects of Cohan's life are glossed over. The movie shows him in a lifelong marriage to his first love. However, he was in fact married in 1899 to Ethel Levy, and after their divorce in 1907 he married Agnes Mary Nolan, who remained his wife until Cohan's death in 1942.
Factual error: The newspaper headline about the sinking of the Lusitania has a photograph of the ship with only two funnels. The Lusitania had four.
Factual error: At the end of the movie, Cohan is shown performing in "I'd Rather be Right," which was a real play. However, one of the lines in the performance is "and now they've taken France." The play ran on Broadway in 1937, but Germany did not invade France until 1940.
Factual error: The movie has Roosevelt presenting Cohan with the Congressional Medal of Honor. Cohan was actually presented the Congressional Gold Medal, which is the nation's highest civilian award. The Medal of Honor is the highest military decoration, awarded for heroism above and beyond the call of duty in combat.