At 630-feet tall, the Gateway Arch is the tallest man-made monument in the United States.

In 1947, architect Eero Saarinen won a contest held by the Jefferson National Expansion Memorial Association. The contest was to design a structure to commemorate Thomas Jefferson and settlers' who made their way into western America.

Construction of the Arch cost $13 million. It weighs 17,246 tons and has extension-footings that extend 60-feet into the Earth.