Fabled Route 66 was opened November 11, 1926, but it would take another year before the signs came up. It starts in Chicago and going through Missouri, Kansas, Oklahoma, Texas, New Mexico, Arizona and California for 2,448 miles before it ends at the pier in Santa Monica, Los Angeles.
The stretch was early legendary because it was the way many were traveling along the West Coast, especially in the 30s with their overcrowded vanload of funiture. It was roughly the Route 66 has changed over the years as the road improves and new routes. Among other things, ended originally downtown Los Angeles and not currently at the pier in Santa Monica.
Today very few parts of Route 66 remains as original.
Source: Nostalgia no 4, 2008