The Second World War (1939-1945) saw the rationing of various items in North America.

Feedsacks were exempt from rationing in order to persuade people to move from the more robust sacking that was needed for the war effort, to lighter and cheaper cotton bags that, as an added benefit, could also be used for clothing and household items. As noted by one American official, Frank Walton (although he apparently underestimated the already existing feedsack industry for clothing):

Millions of yards are required each year for these purposes [feed and flour bags]. Some of these bags when received as a container are even used in many homes for towels and aprons and even dresses. One enterprising concern is even printing a pattern on the fabric to make its conversion to an apron or a dress easier after it has carried the flour to the home (Frank Walton 1945:179).

The use of these sacks and bags was seen as being patriotic and thrifty. At the same time the cloth was marketed as being practical and fashionable. Numerous booklets were distributed to encourage women to produce more and more garments and other items at home, using these simple and US-manufactured materials. At one point it was estimated that three million American women and children were wearing feedsack material in some form or other.

In May 1943, sack and bag sizes were officially defined by the War Production Board in order to help prevent waste and to make it easier for the factories, millers and housewives to know exactly how much material was required. These measurements were based on standard sack capacities of 1, 5, 10, 15, 50 and 100 pounds. A bag that contained five pounds (2.25 kg) of sugar, for example, provided 1/3 yard (33 cm) of cloth, while a 100-pound (45.40 kg) bag provided slightly more than 1 yard (0.915 cm) of material, with four sacks providing enough for one adult woman’s dress. These sizes remained in use for decades.

At the same time, many designs on the cloth reflected American life and important world events. One of the most famous is that produced by the Percy Kent Bag Company and is known as Kent’s Cloth of the United Nations, which was produced in c. 1944. It includes the names of all the allied countries, as well as images of war events, including the campaigns of the British 8th Army in North Africa and of course, Pearl Harbour (7th December 1942). This design became very popular and was reprinted on various occasions. Another side of the story is that millions of sacks were sent to the various war zones throughout the world. As noted by Frank Walton, this caused supply problems:

Foreign shipments have helped to increase our supply problem because these bag containers go out of the country and do not return for further use whereas, when used for delivery in this country [US], they are collected and used several times. While most of the bags that go to a foreign point are used to advantage by the military forces or even by civilians for packaging or clothes, that does not help our problem here. The millions of bags that are going abroad must be replaced, thus increasing the demands here for more cloth (Walton 1945:180).