Gasoline was rationed in 17 eastern states beginning in May 1942 and nationwide in December 1942 — not so much to save fuel as to save tires and the rubber they were made of. A nationwide speed limit of 35 miles per hour was also enforced to save wear on tires. To ration gasoline, the government issued coupon stamps. These “A” stamps were worth three to five gallons of gasoline per week for essential activities such as shopping, attending church, and going to the doctor. The letter on the stamp would have matched a sticker on the car’s windshield. People using their cars for work could buy more gasoline, and truckers could buy all they needed.