With the rising hemlines of the 1920s, stockings became an important part of women's fashion, but silk, the fiber of choice, was expensive and had to be imported from East Asia. Nylon stockings first became available in 1939, when the Second World War had begun to disrupt trade routes, and demand for them quickly outstripped production capacity. After the United States entered the war, nylon became almost unavailable for civilians, and supply did not catch up with demand until well after the war's end in 1945.