Chicago was the eastern terminus of the original U.S. Route 66.
The highway began in the Chicago area and ran westward through Illinois before crossing Missouri, Kansas, Oklahoma, Texas, New Mexico, Arizona, and California. Chicago’s position made it a natural starting point because it was a major transportation hub and one of the largest cities in the United States.
The route’s exact alignment within the Chicago region changed over time. Different road segments served as Route 66 at different periods, and signs or historic markers now identify several surviving alignments.
Travelers sometimes name Springfield or St. Louis because both are strongly associated with Route 66. Springfield is an important Illinois stop, while St. Louis lies just across the Mississippi River in Missouri. Neither, however, was the route’s official eastern terminus; the route began in Chicago and ended at the Pacific coast.