Plot: Land Yachts, Portable Palaces, Corrugated Condos–whatever the name, travel trailers and RVs have become an American icon–the 20th century’s covered wagon. Hit the road as we travel with recreational vehicles–from early versions built on the back of Model-T Fords, to roadside towns known as Hoovervilles during the Depression and WWII “trailer towns” set up for workers near munitions plants or aircraft factories, to modern RVs that resemble mansions on wheels and can cost nearly a million dollars!