In the May 1944 issue of National Geographic, an advertisement shows a U.S. military officer in a dark war room, using a Bell & Howell Filmo projector, instructing troops on "How to STOP a Tank."

"There aren't any Filmo Cameras and Projectors for personal movie making just now," the ad copy reads, "but our postwar products will be well worth waiting for."

After Japanese planes attacked Pearl Harbor, on December 7, 1941—73 years ago today—the United States entered World War II and quickly launched a federal rationing program to support its troops. Government-enforced rationing meant that Americans could buy only limited supplies of common products like shoes, cars, and certain processed foods.