A congressman, the political boss of the Rio Grande Valley and the mayor of Brownsville all told Capt. Bill McDonald of the Texas Rangers on Aug. 24, 1906 that he had made a big mistake by arresting military personnel on federal property.

After losing his father to a Yankee sniper and the family plantation to carpetbaggers, the young Mississippian and his mother took refuge with relatives in east Texas. Handicapped by a poor education, a lack of wage-earning skills and a giant chip on his should...