The Freedom 250 Mobile Museum, known as a Freedom Truck, stands outside the post exchange at Fort Campbell on the Kentucky-Tennessee border. (U.S. Army photo by Jedhel Somera)Some red flags had already popped up in my mind when I visited the Freedom Truck on July 11 in Huron during its three-day stop in that typical, small, welcoming South Dakota city. But after I experienced it, despite its beautiful, engaging, and by-and-large historically acc…