In 1955 General Motors decided to put on a show, not just any show, a gathering of vehicles, horsepower, and entertainment the likes of which the world had never seen before and never saw again. Powerama was a one million square foot fantasyland of every off-highway division of General Motors on display. Dubbed the "World's Fair of Power" it had locomotives, bulldozers, elephants, aircraft, tanks, a submarine, pleasure craft, a shrimp boat, the Motorama dream cars, an 85-ton cannon known as Atomic Annie, and more and more and more. In this history we investigate the genesis of the event, the execution of the event, and the machines that made it one of the most unique gatherings in the gearhead history of Earth. Seriously, this is wild.