In late 1940, Europe was at war while America was still on the sidelines. However, we knew we had to do something, and on December 29 of that year, President Franklin Roosevelt made a speech that would set the auto industry in motion. It would become known as the 'Arsenal of Democracy' speech, and it put Chrysler on a path to making war materiel.
Of course, numerous domestic automakers contributed to the effort, and you can read about all their work in A.J. Baime's book "The Arsenal of Democracy: FDR, Detroit, and an Epic Quest to Arm an America at War." However, Fiat Chrysler Automobiles [NYSE:FCAU] has produced a video documentary outlining Chrysler's efforts to help the Allies defeat Hitler and the Axis powers. At less than six minutes long, it's not overly detailed, but it talks about the tanks, anti-aircraft guns, and trucks Chrysler built for World War II. The documentary also touches on the engineering expertise Chrysler lent to the projects, and how women worked not only in office jobs but also on the factory floor.
This information is imparted by FCA historian Brandt Rosenbusch in front of a surviving military truck, and the video features many vintage images of the tanks and trucks being built on the assembly line. If you are a history buff, this stuff is right up your alley.