Jefferson National Expansion Memorial

Designers: Daniel Urban Kiley, Eero Saarinen | City: St. Louis, MO | Project Type: memorial
Date Visited: 10.07.12

Location: alongside the Mississippi River
Size: 91-acre
Official Opening Date: December 21, 1935

The Jefferson National Expansion Memorial is home to the great silver arc in the sky, the Gateway Arch to the West. Built in remembrance of “Thomas Jefferson’s role in opening the West, to the pioneers who helped shape its history, and to Dred Scott who sued for his freedom in the Old Courthouse,” the park, and in particular, the arch, have become the distinctive and iconic focal points of downtown St. Louis.

In 1803, Thomas Jefferson sealed the deal on the Louisiana Purchase, the transfer of France’s claim on 828,000 square miles of the Louisiana Territory to the United States for $233 million (adjusted for 2011 inflation). By the terms of a present-day U.S. map, that territory encompasses all or part of 15 current U.S. states and two Canadian provinces–from the Mississippi River on the east to as far as portions of Montana on the west. After the Louisiana Purchase, St. Louis’ role as a gateway to western expansion was further strengthened when it was also recognized as being close to one of the starting points for the Lewis and Clark Expedition.

The iconic, stainless steel Gateway Arch is the centerpiece of the Jefferson National Expansion Memorial and is also the nation’s tallest monument at 630-feet–it has 75 feet over the Washington Monument. Designed by the architect Eero Saarinen and structural engineer Hannskarl Bandel in 1947, Saarinen used the catenary–the shape of a perfectly flexible chain suspended by its ends and acted upon by gravity–as the basis of his design. The final geometric form was then determined by a series of precise mathematical equations, specifically from the hyperbolic cosine function. The catenary should be of significance to many architects and engineers due to its frequent appearance in bridges and arches.

First stage competition entry. Photo Credit:

Working alongside Saarinen to create the classical landscape design for the park was the famous contemporary landscape architect Dan Kiley. Together, they mapped out a symmetrical plan with special attention paid to axial relationships and monoculture tree-lined walkways, accented by sweeping, curved walkways to mirror the graceful arcs of the Gateway Arch. The spatial organization of the landscape was also carefully considered; Kiley sought a balance between areas of open green space and dense tree canopy.

Although the Jefferson National Expansion Memorial landscape has been filed as a Historic Landscape, the city of St. Louis held the international design competition The City+The Arch+The River in 2010 for a redesign of the Gateway Arch grounds, with the hope that a redesign–whilst keeping many of Kiley and Saarinen’s ideas intact–will better connect the Memorial grounds with downtown St. Louis. Michael Van Valkenburgh Associates (MVVA), the Brooklyn-based landscape architecture firm, won the contract with a project completion deadline of October 28, 2015–just in time for the Gateway Arch’s 50th Anniversary.

MVVA’s Site Plan. Image Credit: For more concept images, click here.

MVVA’s Concept Imagery. Image Credit: For more concept images, click here.

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