Henri and Camille Dreyfus, brothers from Switzerland, set up several factories devoted to the manufacture of cellulose acetate in the early 1900s. One of the uses of cellulose acetate was as aircraft dope to waterproof and harden the fabric covering airplane wings. At the onset of World War I, aircraft dope was in great demand. The Dreyfus brothers soon focused their efforts solely on the manufacture of aircraft dope and in 1917 agreed to build a factory in Cumberland, Maryland. This factory, however, was not completed until after the end of World War I.