The Butterfield Overland Mail Trail was a stagecoach service in the United States, operating from 1857 to 1861. It carried passengers and U.S. Mail from two eastern termini, Memphis, Tennessee and St. Louis, Missouri to San Francisco, California. The routes from each eastern terminus met at Fort Smith, Arkansas, and then continued through Indian Territory, Texas, New Mexico, Arizona, Baja California, and California ending in San Francisco. On March 3, 1857, Congress under James Buchanan authorized the U.S. postmaster general, Aaron Brown, to contract for delivery of the U.S. mail from Saint Louis to San Francisco. Prior to this, U.S. Mail bound for the Far West had been transported by ship across the Gulf of Mexico to Panama, where it was freighted across the isthmus to the Pacific, then taken by ship for points in California.
Through the 1840s and 1850s there was a desire for better communication between the east and west coasts of the US. Though there were several proposals for railroads connecting the two coasts, a more immediate realization was an overland mail route across the west. Congress authorized the Postmaster General to contract for mail service from Missouri to California to facilitate settlement in the west. The Post Office Department advertised for bids for an overland mail service on April 20, 1857. Bidders were to propose routes from the Mississippi River westward.
John W. Butterfield and his associates William B. Dinsmore, William G. Fargo, James V. P. Gardner, Marcus L. Kinyon, Alexander Holland, and Hamilton Spencer created a proposal for a southern route from St. Louis to California. The Post Office Department received nine bids. The Postmaster General, Brown, was from Tennessee and favored a southern route. Although none of the bidders had provided for the route, the Postmaster General advocated a southerly route, known as the Oxbow Route, with the idea that it could remain in operation during the Winter.