Based on a true story and a play by Rida Johnson Young, Napoleon's brother falls in love with an American and wants to marry her.
Napoleon Bonaparte (Claude Rains) offers $20,000,000 for the Louisiana territory and sends his brother Jerome Bonaparte (Dick Powell) to America. Charles Patterson (Henry Stephenson) tells Aunt Ellen that Jerome is coming, while Henry (Charles Ruggles), John (Edward Everett Horton), and Sir Harry (Arthur Treacher) court his daughter Betsy Patterson (Marion Davies). At a horse race Jerome laughs at Betsy's French and wins a bet to spend the afternoon with her. He sings in French, and she helps a black boy find his Mammy. Jerome is hired under a pseudonym as Betsy's French tutor and music teacher, and he sings "My Kingdom for a Kiss." He loves her; but when he calls her a snob, she fires him. Jerome defends Napoleon to John and Charles, who discharges him. Betsy apologizes to Jerome; but he can't go to Washington with them.
Napoleon sells Louisiana for 80,000,000 francs and orders Jerome to attend ceremonies. Betsy tells Aunt Ellen she loves her tutor. During the Patterson reception Jerome sings to Betsy's balcony and embraces her in the garden. Then he enters the house and is announced as Captain Jerome Bonaparte. John, Henry, and Harry drink to see who will propose to Betsy. Charles announces the betrothal of Betsy to Jerome; but he gets a letter from Napoleon that he must wed the princess of Wurtemberg. Jerome says he will disobey, and Betsy suggests she go to France with him. She translates the letter to all as asking her to marry in France.
On the ship the consul reads an order from Napoleon for Jerome to leave Betsy on the ship. Jerome says he will go to America, as Napoleon comes in. Alone with Betsy, Napoleon toasts her victory and speaks of France. She admires his patriotism. Napoleon says Jerome will hate himself for betraying France and begs Betsy to sacrifice bravely. She agrees to give him up and boards the ship for America without telling Jerome.
Jerome accuses Napoleon of deception; but their mother (Beulah Bondi) pleads that maybe Jerome does not want to be king of Westphalia. Charles welcomes Betsy home. Henry, John, and Harry asks Betsy to choose; but she wants to keep all three as friends. She hears the singing of Jerome, and they kiss.
Jerome Bonaparte did marry Betsy Patterson; but after a year and a half he threw her over and wed Princess Catherine of Wurtemberg to become king of Westphalia. This romantic story shows a true conflict between personal love and power politics.