USDA head Claude R. Wickard banned the sale of pre-sliced bread on January 18, 1943, as part of the war effort. The rationale was that unsliced bread could get by with a lighter weight wrapper. The ban was rescinded in March because the savings weren't as great as expected and bakers were supplied with "sufficient waxed paper" as a result. So there went somebody's keen idea, right out the window.