A reference is made to a headline, "Nazis Sweep Through Norway," placing this film as taking place in April 1940. The Germans had invaded Norway on April 9. The movie was filmed from December 1944 through February 1945; it was not released until a year later, in February 1946. By that time, supporting player Henry Armetta had already been dead. (heart attack) for several months.
Cousin Willie quotes William Shakespeare when speaking to Jesse Bibbs, the bank manager: "We are such stuff as dreams are made on." ("The Tempest", Act 4, scene 1, 148-158)
The WPA was the Work Progress Administration (formerly the Works Projects Administration). It was created by President Franklin D. Roosevelt in 1935 to create employment and revitalize communities across the US. It was part of his New Deal strategy.
Cousin Emma paraphrases Admiral David Farragut " Damn the torpedoes, full speed ahead." More than likely this was an inside joke towards Charles Coburn who delivered that quote multiple times in "The More the Merrier" (1943) in which he co-starred with Jean Arthur.