The Gateway Arc

The Gateway Arch in January 2008

Alternative names : Gateway to the West
General information
Architectural style :  Structural expressionism[1]
Location : Memorial Drive, St. Louis, Missouri, United States
Coordinates : 38.62452°N 90.18471°WCoordinates: 38.62452°N 90.18471°W
Construction started :  February 12, 1963
Completed : October 28, 1965
Inaugurated : May 25, 1968
Cost : US$13 million ($90,491,005 today[2])
Height:  630 ft (192 m)
Design and construction
Main contractor : MacDonald Construction Co.
Architect : Eero Saarinen
Architecture firm  :  Saarinen and Associates
Structural engineer :  
Hannskarl Bandel
U.S. National Register of Historic Places
U.S. National Historic Landmark
Governing body : National Park Service
NRHP Reference# :  87001423
Significant dates
Added to NRHP : May 28, 1987[3]
Designated NHL :  May 28, 1987[4]

            The Gateway Arch, or Gateway to the West, is an arch that is the centerpiece of the Jefferson National Expansion Memorial in St. Louis, Missouri. It was built as a monument to the westward expansion of the United States. At 630 feet (192 m), it is the tallest man-made monument in the United States, Missouri's tallest accessible building, and the largest architectural structure designed as a weighted or flattened catenary arch.

           Located on the west bank of the Mississippi River where the city of St. Louis was founded, the arch was designed by Finnish American architect Eero Saarinen and structural engineer Hannskarl Bandel in 1947. Construction began on February 12, 1963, and ended on October 28, 1965, costing US$13 million at the time ($90,491,005 today). The monument opened to the public on June 10, 1967.

The arch is located at the location of St. Louis' foundation in 1764—on the west bank of the Mississippi River where Pierre Laclède, just after noon on February 14, 1764, told his aide, Auguste Chouteau, to build a city. 

         Originally December 20, the bidding date was postponed to January 22, 1962, to clarify the details of the arch construction. About 50 companies that had requested the construction requirements received bidding invitations. Extending from $11,923,163 to $12,765,078, all four bids exceeded the engineer estimate of $8,067,000. Wirth had a committee led by George Hartzog determine the validity of the bids in light of the government's conditions. Following a meeting with the bidders, the committee affirmed the bids' reasonability, and Wirth awarded the lowest bidder, MacDonald Construction Company, the contract for the construction of the arch and the visitor center. On March 14, 1962, he signed the contract and received from Tucker $2,500,000, the city's subsidy for the phase. MacDonald reduced its bid $500,000 to $11,442,418.

            In 1959, ground was broken, and in 1961, the foundation of the structure was laid. Construction of the arch itself began on February 12, 1963. Steel triangles that narrowed as they spiraled to the top were raised into place by a group of cranes and derricks. The arch was assembled of 142 12 feet(3.7 m)-long prefabricated stainless steel sections. Once in place, each section had its double-walled skin filled with concrete, prestressed with 252 tension bars. In order to keep the partially completed legs steady, a scissors truss was placed between them at 530 feet (160 m), later removed as the derricks were taken down. The whole endeavor was expected to be completed by fall 1964, in observance of St. Louis' bicentennial.

Contractor MacDonald Construction Co. arranged a 30-foot (9.1 m) tower for spectators and provided recorded accounts of the undertaking. The project manager of MacDonald Construction Co., Stan Wolf, said that a 62-story building was easier to build than the arch: "In a building, everything is straight up, one thing on top of another. In this arch, everything is curved.