Where is the Butterfield Route located?

The Butterfield Route, also known as the Butterfield Overland Mail Route, was a historic stagecoach route that ran from St. Louis, Missouri, to San Francisco, California. Established in 1858, it primarily traversed through the southern United States, including parts of Texas, Arizona, New Mexico, and California. This route played a crucial role in facilitating mail and passenger transport during the mid-19th century, connecting the eastern and western United States.