US 30 was originally proposed to run from Salt Lake City, Utah to Atlantic City, New Jersey. West of Philadelphia, Pennsylvania, this was designated largely along the Lincoln Highway, as part of a promise to the Lincoln Highway Association to assign a single number to their road as much as possible. West of Salt Lake City, U.S. Route 40 continued to San Francisco, California, although it ran farther north than the Lincoln Highway east of Wadsworth, Nevada and west of Sacramento, California.