James Morrow Walsh can rightfully be called the orginal Mountie. In late 1873 he led the first troop of scarlet-coated policemen toward the great Canadian prarie. In the summer of 1875 he was assigned to construct Fort Walsh in the Cypress Hills above the U.S. border. Below the border, or medicine line as the Sioux Nation knew it, 15,000 Native Americans were drawn a year later to the camp of Sitting Bull on the LIttle Bighorn River. By 1877, newspaper headliners from Chicago to New York...