This trailer hitch was a real fifth wheel

Did you know that famed aviation pioneer Glenn H. Curtiss also pioneered travel trailers? He was working on them early as 1917. He wasn't satisfied with the hitches of those early days, so he developed his own, the first fifth wheel hitch for trailers.

Curtiss mounted an actual wheel and tire horizontally over the rear axle of the tow car using four clamps in a square frame. The pin on the trailer was locked into the hub of the wheel. The inflated tire helped to dampen road vibrations and shocks, improving the ride and reducing wear and tear on the trailer. His hitch and the trailers he also designed were sold up until about 1940. Check out a restored 1936 Curtiss Aerocar Land Yacht.