Maybe they were Civil War buffs, on their way to reenact the attack on Fort Sumter.
"Vehicle with explosives stopped in US," from Deutsche Presse Agentur (thanks to rocketsbrain):
Washington (dpa) - Local police outside Charleston, South Carolina stopped a vehicle in which they found what were suspected to be explosives, according to media reports late Saturday.Posted at August 5, 2007 7:31 AMTwo men described as being of possibly Middle Eastern origin were in the vehicle, which was stopped on a highway. A police bomb squad was at the scene and preparing to examine the vehicle, a local television reported told the Cable News Network (CNN).