The United States has dominated the automobile industry since the industry began at the beginning of the twentieth century. Although Europeans had hand-built automobiles, the mass production of automobiles using standardized, interchangeable parts and the assembly line was an American invention. Henry Ford developed the moving assembly line in 1913 in order to produce his famous Model T Ford car cheaply for a mass market, and it revolutionized industrial production. Although there were many smaller companies, by the early 1920s, the “Big Three”—Ford, General Motors, and Chrysler dominated the U.S. market. The automobile industry boomed during World War II with the production of vehicles and other materials for military use. After the war, the industry met the growing consumer demand for automobiles, and companies began to compete with attractive styling and model variety as well as technological innovations. Fancy new American cars became an essential part of the American Dream in the 1950s, and the development of a national highway system promoted the use of the automobile for recreational travel.