There was originally a song that echoed "Hurray for Captain Spaulding" entitled "Dr. Hackenbush" (written by "Spaulding" songwriters Bert Kalmar and Harry Ruby). However, it was decided that something needed to be cut and Groucho Marx volunteered this song. He came to regret this this decision and in later years often sang the song at gatherings.
Groucho Marx's character was initially to have been named Dr. Quackenbush, which he and everyone else thought was too silly a name to offend anyone. However, MGM's legal department discovered at least a dozen legitimate U.S. doctors named Quackenbush, so for legal reasons the name was changed to Hackenbush. Although initially dismayed by the name change, Groucho later came to like it. He cited "Dr. Hackenbush" as his favorite character from his films, and even occasionally signed letters to friends using that name.
This is the only film of The Marx Brothers to receive an Oscar nomination in a competitive category, being nominated for Dave Gould's dance direction. Groucho Marx would go on to win an honorary Oscar in 1974.
The "Grand Steeplechase" sequence at the end had to be shot twice. Both times a crew member persuaded Chico Marx to gamble on it and not only to bet on the outcome of a rigged non-race, but to bet on a horse other than the one scripted to win. Chico, all his life an avid gambler, could offer as excuse only, "The odds were 20 to one."
Al Boasberg, the man most responsible for shaping the early comic persona of Jack Benny, was initially given top billing among the film's writers. In what was to become one of the first major disputes over film writing credit, Boasberg (primarily a gag man) sought sole credit for the comedic scenes, leaving credit for the screenplay itself to Robert Pirosh and George Seaton. MGM bitterly fought this and punished Boasberg by listing him under the others. A furious Boasberg had his name removed from the film completely.