Which major highway connects Oklahoma to California and Chicago?

The major highway that connects Oklahoma to California and Chicago is U.S. Route 66. This historic route, often referred to as the "Main Street of America," stretches from Chicago, Illinois, to Santa Monica, California, traversing multiple states, including Oklahoma. It played a significant role in the migration of Americans westward during the mid-20th century and became a symbol of American cultural and automotive history.

While Interstate 40 does run through Oklahoma and connects to California, it was built later and is not part of the original route that linked Chicago and the West Coast, as U.S. Route 66 was. Interstate 35 primarily connects points north and south within the central United States rather than serving as a direct link to either California or Chicago. U.S. Route 81 has historical importance but does not serve as a major connector to both destinations.