The Gateway Arch dates as far back as 1947. The arch was designed by Ero Saarinen and Hannskarl Bandel. There are three important events in the American history that the Gateway Arch signifies. Fore mostly it was built to show the expansion of USA towards west. But three important historical events that led to the construction of this memorial are the Louisiana Purchase, the construction of Cathedral Basilica in St. Louis and the Dred Scott case.
The construction finally started in 1963 and it took two years to complete it. The Gateway Arch is made in shape of a centenary curve. The total length covered by the Arch is 630 feet from one end to the other. Interestingly it also rises to the height of 630 feet. The Arch is steel plated and was also designed in such a way that it appears to be swaying in wind. The Arch has concrete foundations to stabilize its base.