"Remember, boys, nothing on God's earth must stop the United States mail!" said John Butterfield to his drivers. Short as the life of the Southern Overland Mail turned out to be (1858 to 1861), the saga of the Butterfield Trail remains a high point in the westward movement. A.C. Greene offers a history and guide to retrace that historic and romantic Trail, which stretches 2800 miles from the Mississippi River to the Pacific coast.