How long was the original U.S. Route 66, in miles?

The original U.S. Route 66 was 2,448 miles long.

That figure describes the recognized historic highway between Chicago, Illinois, and Santa Monica, California. It crossed eight states and connected the Midwest with the Southwest and Pacific coast, making it one of the best-known long-distance roads in the United States.

The number can vary in informal descriptions because Route 66 was repeatedly realigned. Sections were straightened, bypasses were built, and the western endpoint shifted from Los Angeles to Santa Monica in 1936. Historic tours may therefore follow an older alignment or a later one.

The 2,448-mile figure is the standard length listed for U.S. Route 66. It refers to the highway as a national route, not to every surviving pavement segment. After decommissioning, different states preserved portions under Historic Route 66 designations.