Diamond Station was a stop along the nearly 700-mile stretch across the Lone Star State for the Butterfield Overland Mail Stage Line Company, which held the U.S. Mail contract for the first cross-country trek from St. Louis to San Francisco. Marked as the first intercontinental mail route, the Butterfield Overland Mail Stagecoach made its first stop at Diamond Station on September 21, 1858. The complete route took 24 days and covered 2,812 miles, carrying mail and passengers. At this location Waterman Ormsby witnessed "the operation of harnessing a wild mule." He estimated it took 30 minutes per mule, and four were used. John R. Diamond kept the station from 1858 to 1861.