How many miles long was historic U.S. Route 66 from Chicago to Santa Monica?

Historic U.S. Route 66 was 2,448 miles long from Chicago, Illinois, to Santa Monica, California.

The highway was established in 1926 as one of the original routes in the United States Numbered Highway System. It crossed eight states and linked the Midwest with the Pacific coast, becoming a major corridor for migration, freight, and tourism.

The mileage refers to the historic route rather than one single modern road. Route 66 was repeatedly realigned, and different maps may measure older or later alignments slightly differently. That is why visitors sometimes encounter varying mile totals in travel guides.

Route 66 was removed from the national highway system in 1985, but many sections remain drivable as Historic Route 66. Its 100th anniversary in 2026 celebrates the route's 1926 creation.