During the World Wars, women’s corsets weren’t just a matter of fashion. They became a matter of national security.

In World War I, the U.S. War Industries Board urged women to stop wearing corsets, since each garment used metal stays. By giving them up, American women freed up an estimated 28,000 tons of steel, enough to build two battleships.

By World War II, corsets had already started slipping out of fashion, but rationing sealed their fate. The U.S. War Production Board restricted metal use, and in Britain, the Board of Trade regulated clothing under “Utility” rules. Corsets were redesigned with little or no steel, and women were encouraged to conserve every scrap of material for the war effort.