The immediate surroundings of the Gateway Arch were initially designated the Jefferson National Expansion Memorial by secretarial order on December 21, 1935.

It was designed by the Finnish-American architect Eero Saarinen and the German-American structural engineer Hannskarl Bandel in 1947 and built between 1963 and October 1965.

To the west of the Old Courthouse is the Gateway Mall between Market and Chestnut Streets which is only interrupted by the Civil Courts Building which features a pyramid model of the Mausoleum of Mausolus (which was one of the Seven Wonders of the Ancient World) on its roof.

The new museum features exhibits on a variety of topics including westward expansion and the construction of the Arch, all told through a St. Louis lens.

Tucker Theater, finished in 1968 and renovated 30 years later, has about 285 seats and shows a documentary (Monument to the Dream) on the arch's construction.

The memorial was developed largely through the efforts of St. Louis civic booster Luther Ely Smith who first pitched the idea in 1933, was the long-term chairman of the committee that selected the area and persuaded Franklin Roosevelt in 1935 to make it a National Park Service unit after St. Louis passed a bond issue to begin building it and who partially financed the 1947 architectural contest that selected the arch.

Shortly after Thanksgiving in 1933 Smith who had been on the commission to build the George Rogers Clark National Historical Park in Indiana, was returning via train when he noticed the poor condition of the original platted location of St. Louis along the Mississippi.

Smith pitched the idea to Bernard Dickmann who quickly assembled a meeting of St. Louis civic leaders on December 15, 1933, at the Jefferson Hotel and they endorsed the plan and Smith became chairman of what would become the Jefferson National Expansion Memorial Association (a position he would hold until 1949 with a one-year exception).

The Commission then defined the area, got cost estimates of $30 million to buy the land, clear the buildings and erect a park and monument.

With promises from the federal government (via the United States Territorial Expansion Memorial Commission) to join if the City of St. Louis could raise money.

Local architect Louis LaBeaume provided a preliminary design proposal for the site that included multiple museums, fountains and obelisks.

Architect Eero Saarinen won this competition with plans for a 590-foot (180 m) catenary arch to be placed on the banks of the Mississippi River.

However, these plans were modified over the next 15 years, placing the arch on higher ground and adding 40 feet (12 m) in height and width.

The family celebrated with a bottle of champagne, and two hours later an embarrassed official called to say the winner was, in fact, the younger Saarinen.

On February 12, 1963, the first stainless steel triangle that formed the first section of the arch was set in place on the south leg.

As well, the Ulysses S. Grant National Historic Site in St. Louis County, Missouri, was put under the jurisdiction of the Superintendent of the Memorial.

In 2007 St. Louis Mayor Francis Slay and former Missouri Senator John Danforth asked the National Park Service to create a more "active" use of the grounds of the memorial and model it on Millennium Park in Chicago including the possibility of restaurants, fountains, ice skating, swimming, and other activities.

In September 2010 Michael Van Valkenburgh Associates won a design contest to "re-envision the visitor experience" of the grounds.

[21] On June 26, 2017, Senator Roy Blunt (R-Missouri) introduced the Gateway Arch National Park Designation Act (Pub.

U.S. President Donald Trump signed the act into law on February 22, 2018, officially renaming the site Gateway Arch National Park.

Among the partners leading this project are the Arch to Park Collaborative, St. Louis City, and Washington University in St.