The whole surrounding park was created in memory of a number of things:
- The Louisiana Purchase: the United States in 1803 were expanded to include an area of 2.1 million km2. Symbolically are millions of settlers under the Arch extended. After that time were the first States founded West of the Mississippi .
- The Dred Scott Case: a lawsuit to the debate on slavery left a flare up.
The structure was designed by Eero Saarinen and Hannskarl Bandel. It has the form of a mathematical catenary and is built entirely of double-walled stainless steel separated by a layer of concrete. The intersection is everywhere triangular. It is 192 metres high and at the base also 192 metres wide. The construction lasted from February 12, 1963 to 28 October 1965 and cost 15 million dollars. It is the second highest building of the State of Missouri. The highest is the One Kansas City Place in Kansas City. Inside the monument drive two trams that bring visitors to the observation deck at the top of the set.