US 40 is one of the most important and historic highways in the United States. Its route runs over the National Road, the United States' first federally funded road and comprised the western half of the Lincoln Highway.
From 1926 to 1964, US 40 was a transcontinental highway and its route covered a lot of American history. It went next to the Oregon Trail and the ruts from the covered wagons could be seen from cars going down the road at high speeds. The highway followed in many places the route of the ill-fated Donner party and went through the pass that bears their name. It also went right next to Sutter's Mill in Sacramento where the discovery of gold changed the course of US history and ended in San Francisco, the final destination for many seeking a better life.