Rufus T. Firefly is named president/dictator of bankrupt Freedonia and declares war on neighboring Sylvania over the love of wealthy Mrs. Teasdale.

Clips from assorted television programs, B-movies, commercials, music performances, newsreels, bloopers, satirical short films and promotional and government films of the 1950s and 1960s are intercut together to tell a single story of various creatures and societal ills attacking American cities.

During the Florida land boom, the Marx Brothers run a hotel, auction off some land and thwart a jewel robbery.

Jeff Wilson, the owner of a small circus, owes his partner Carter $10,000. Before Jeff can pay, Carter's accomplices steal the money so he can take over the circus. Antonio Pirelli and Punchy, who work at the circus, together with lawyer Loophole try to find the thief and get the money back.

A con man heading west to search for gold teams up with a pair of scheming brothers along the way. The trio soon find themselves in the middle of a feud between two rival families and two underhanded land developers.

Doctor Hugo Hackenbush, Tony, and Stuffy try and save Judy's sanitarium by winning a big race with a finicky horse owned by Judy's boyfriend Gil. There are a few problems. Hackenbush, who was recently put in charge of the sanitarium, isn't really a doctor, he's a veterinarian.

The Marx Brothers are employed at a hotel in postwar Casablanca, where a ring of Nazis is trying to recover a cache of stolen treasure.

Ex-gangster Tony Banks is called out of retirement by mob kingpin God to carry out a hit on fellow mobster "Blue Chips" Packard. When Banks demurs, God kidnaps his daughter Darlene on his luxury yacht.

A detective is hired to protect the life of a singer, who has recently inherited a department store, from the store's crooked manager.

The Marx Brothers help young Broadway hopefuls when they get mixed up with gangsters due to a tin of sardines containing Romanoff diamonds.