In 1865, a unit of cavalry soldiers thought they had volunteered to fight in the Civil War. Instead, they found themselves sent west to defend pioneer settlers against angry Sioux Indians in what is now South Dakota. Upon their arrival, the soldiers built Fort James, one of the few stone forts on the American frontier. The fort's quartzite walls still peek out from under a grassy field that seems to have somehow survived intact. The site has never been excavated, but experts believe that the fort's remains hold a time capsule of information about life on the early frontier. Time Team America traveled to South Dakota on a rescue mission: to find out how much of the fort survives and how big an area it covers so that the archaeology can be protected for future research.