Jefferson National Expansion Memorial consists of the Gateway Arch, the Museum of Westward Expansion, and St. Louis' Old Courthouse. During a nation-wide competition in 1947-48, architect Eero Saarinen's inspired design for a 630-foot stainless steel arch was chosen as a perfect monument to the spirit of the western pioneers.

Construction of the Arch began in 1963, and was completed on October 28, 1965, for a total cost of less than $15 million. The Arch has foundations sunk 60 feet into the ground, and is built to withstand earthquakes and high winds; it sways up to 1 inch in a 20 mph wind, and is built to sway up to 18 inches. A Grand Staircase leads from the St. Louis levee up to the base of the Gateway Arch.

Information provided by the Historical Marker Database and the National Park Service.

http://www.hmdb.org/marker.asp?marker=26866