A princess finds love with a regular American Joe in this patriotic romantic comedy. A European diplomat (Charles Coburn) is named an ambassador to the U.S., and when he relocates to Washington D.C., he's accompanied by his niece, Princess Maria (Olivia de Havilland). Maria's uncle hopes that she'll meet an eligible American bachelor during her visit, since potential husbands are in short supply at home. Maria tires of her uncle's attempts at matchmaking, and when he suggests that she take a side trip to San Francisco, she leaps at the chance. However, Maria has a fear of flying, and when she's given tranquilizers to settle her nerves, she passes out in mid-flight. Maria is down for the count when bad weather forces the flight to return to Washington, and pilot Eddie O'Rourke (Robert Cummings) volunteers to put her up for the night. When Maria comes to, she's struck by Eddie's decency and charm, and it's love at first sight for them. However, Maria's uncle was hoping for someone higher up the social ladder than a pilot, and the lovebirds have an uphill battle getting him to consent to their wedding. No one seems sure if it's actually President Franklin D. Roosevelt appearing in the film's final scenes or just an impersonator, but apparently FDR's dog Fala did actually play himself.