The Jefferson National Expansion Memorial Association was formed by St. Louis residents in 1933 with the hope of revitalizing their downtown waterfront through investment in a civic development commemorating the city’s role in American westward expansion. Having gained congressional support to pursue the project through means of the National Park Service, the Federal Government began acquiring Riverfront district properties in 1936, demolishing them in a window from 1940-41 before progress was halted by the war. When the project resumed in 1947, a national competition was held to select a design for the memorial, bringing in submissions from a number of high profile American architects and more than 200 applicants overall. Beyond seeking a monument to commemorate President Jefferson, the brief called for an open air “campfire theater”, limited reconstruction of historic buildings, a museum devoted to Westward Expansion, recreational facilities, parking accommodations, and plans to relocate a railroad running through the site (Architectural Record, April. 1947). The winning design came from a team consisting of architects Eero Saarinen and J. Henderson Barr, sculptor Lily Swann, landscape architect Dan Kiley, and designer Alexander Girard. Their entry effectively met the varied components of the competition, but was squarely dominated by the focal gesture of Saarinen’s monumental parabolic arch. In the intervening decade, while complications around the rail line delayed construction, the crowded plan was simplified and meticulously refined; leaving The Arch alone in a landscape crafted to echo and elevate its profile against the dramatic dual backdrops of St. Louis and the Mississippi River. 

From 2005 to 2015, Wiss, Janney, Elstner Associates investigated and addressed sources of staining and discoloration on the stainless steel skin. 

From 2015 to 2018, the firms of Cooper Robertson and James Carpenter Design Associates expanded the underground museum portion of the memorial, providing new space to accommodate a more complex, inclusive, and interpretive portrait of westward expansion. A new museum entrance was excavated on the western edge of the central mall, and in coordination with Michael van Valkenburgh Associates, pedestrian access between the park and the city was bridged with a new landscaped plaza across Interstate 44. Valkenburgh Associates also paved thousands of linear feet worth of new accessible trails through the greenspaces around Kiley’s original circulation plan.

The complex and its structures continue to serve as a monument, national park, and visitor center. 

Between recent maintenance and renovation projects, the park, Arch, and museum facilities are in excellent condition. The new entrance and pathways were executed with care not to intrude on or drastically alter the original landscape, but regardless constitute substantial alterations to the site’s original scheme. 

Gateway Arch National Park spans the greater length of the St. Louis downtown riverfront, stretching roughly 0.7 miles between two Illinois-bound bridges, and 0.2 miles between Interstate 44 and a low sloping levee. A central mall bisects the park widthwise, with The Arch rising from its eastern half, and a pair of perpendicular esplanades branching symmetrically beside it. Twin pairs of curving tree lined paths outline these pedestrian axes. Separated by a grassy median, they narrow before diverging to connect with the eastern and western park entrances on their respective north and south ends. In the two western pockets of green space, demarcated by the mall, paths, and highway, periodic clusters of native trees fill the sunken landscape, surrounding a free form geometric pond at the center of each region. The southern of these two self-contained landscapes additionally features the 1834 Basilica of St. Louis, one of the two remaining buildings from the nineteenth century riverfront; the other being the Old Courthouse, managed by the NPS as well. At the far east edge of the mall, a 65 step grand staircase descends to the levee, flanked to either side by trenches contoured to blend with the landscape. The concrete lined troughs expose the rail line which crosses the park, otherwise buried under the mall or concealed in the retaining walls at the park’s eastern and western extremities. 

Modeled to the proportions of a catenary curve, The Arch reaches both a maximum height and span of 630’. The sides of its triangular cross-section measure 54’ where the legs meet the ground, and taper to 17’ as they join at the top. A composite stressed skin, of which the stainless steel exterior forms the outer layer, provides all necessary structural support, leaving the interior cavity free to house escape stairwells and mechanical carriage tracks in each leg. An observation deck is enclosed at the top of The Arch with an 80 person capacity. 

Ramps leading below ground from the inner sides of The Arch provide surface access to the original Saarinen museum space, a hypostyle hall supported by downward tapering cruciform columns and a deep waffle slab, all constructed in reinforced concrete. The tram carriages are accessed from this subterranean space, and the new museum expansion with its larger entrance connects to the west.  

The Arch’s structural membrane consists of ¼” stainless steel exterior plates and ⅜” interior carbon steel plates. The layers are separated by post-tensioned concrete up to the 300’ mark, above which plate steel diaphragms bridge the interstitial gap. The two legs were constructed simultaneously without supportive scaffolding; each leg having sufficient strength and foundational security to remain cantilevered and freestanding until the final keystone segment was placed. The task of raising finished triangular segments for installation was handled by two 100-ton “creeper” cranes, which rode along rails secured to the outward faces of the legs.

Gateway Arch National Park is bound north and south by bridges crossing the Mississippi to Illinois. The historic 1867 Eads bridge carries street traffic to the north and 1967 Poplar St. Bridge serves Interstate 55 and 64 to the south. Sunken below grade, Interstate 44 forms the park’s western boundary, with three elevated crossings connecting the park to downtown St. Louis. The blocks adjacent to the park over the highway are lined with postwar highrises, with the exception of a landscaped plaza which connects the central mall to the 1816-65 Old Courthouse; a prominent site in civil rights history for having seen the preliminary ruling of the infamous Dred Scott case. Lenor K. Sullivan boulevard runs along the eastern perimeter of the site atop a concrete surge wall, beyond which the gentle brick embankment of the St. Louis levee sprawls into the Mississippi. 

In his ceaseless campaign to bring, “form or visual order to [] industrial civilization,” Eero Saarinen was an enthusiastic pioneer of new technical possibilities in architecture (Temko 20). Oftentimes this meant the introduction of existing technologies from other fields of application, to architectural challenges in which their use was foreign; a strategy he referred to as “technological transfer” (Serraino 13). Unlike neoprene or corten steel, confined for decades to industrial design and civil engineering before adoption in Saarinen’s work at GM and John Deere, stainless steel was readily embraced by architects soon after its invention (Prudon 119). It was however, overwhelmingly limited to use in decorative cladding or trim at the time Saarinen’s team planned their entry to the Jefferson competition. What Saarinen desired was to combine this leading aesthetic expression of modern material sciences, with the strength, permanence, and dignity which masonry alone had offered to monuments of the past (Temko 18,19). In resolving these aspirations, Saarinen’s winning design came to rely on the ductile strength of its perimeter shell, employing a “stressed skin” structural concept more familiar to aeronautics than architecture at the time. 

The composite skin developed with Fred Severud was an exceedingly unique synthesis of steel and concrete, even amid bold and widespread experimentation with both materials in the postwar decades. While the exact composite membrane and structural properties of The Arch’s construction were not adapted for use in tall buildings, as engineer Hannskarl Bandel proposed in 1963, the innovations did prefigure a widening field of tensile engineering in architecture (Architectural Forum, Nov. 1963).

Contrasting the humanistic aspirations of Saarinen’s modernism with the problematic mythos of Westward Expansion, the Gateway Arch’s complex identity has evolved alongside shifting understandings of American history. When the design competition was held, a mere four years after John Russel Pope’s neoclassical Jefferson Memorial was completed in Washington D.C., it was clear that attitudes towards federal character had shifted drastically in civic and architectural communities alike. New expressions of modernity had come to symbolize, not only prosperity, but the free and democratic ideals of the emerging international community. The Jefferson National Expansion Memorial was planned at a time when conventional wisdom positioned Thomas Jefferson foremost as a symbol of democracy, and Westward Expansion as an astounding feat of human strength and spirit. Saarinen addressed these formidable icons of social and material progress with the bold symbolic and structural content of his design. As more inclusive and critical histories of the US have come to enlighten popular consciousness however, the violence and dispossession of both American expansionism and Jefferson’s himself have receded to a position of more nuanced, honest, and impartial commemoration in the park’s museum; while the Arch and its symbolic act of regional connection have become the independent focus of the park’s dignity and celebration. Saarinen’s premier contribution to the modern search for monumental expression succeeds in the goodwill and flexibility of its noble abstraction. As Walter Gropius asserted, “the old monument was the symbol for a static conception of the world, now overruled by a new one of relativity through changing energies" (Albrecht 296). The accommodation of “changing energies” is precisely the attribute which has allowed Gateway National Park to endure as a symbol of national pride, even as the exact paradigm around its conception has collapsed and transformed. 

As leading models of commercial, residential, and civic modernity solidified in the postwar years, the challenge of conceiving a memorial in modern terms showed less decisive direction. Eero Saarinen once declared of his profession, "the only architecture which interests me is architecture as fine art” (Soullière Harrison 7). His monumental solution for the Expansion Memorial Competition provided him with his most direct opportunity to conceive of architecture in such pure terms. Originally trained as a sculptor, the search for plastic expression is a binding thread throughout his career. Discerning sources of appropriate sculptural opportunity and refining control of his response, he was deeply attentive to conditions of structure, siting, material, and movement. With the museum concealed below ground, the Gateway Arch and surrounding park reduce to a fundamental balance of these factors, and their effective potential to communicate the dignity and grandeur of monumental civic expression. The formal relationship between architecture, space, and landscape becomes an act of pure sculpture. 

The siting and context of Gateway Arch National Park is fundamentally related to movement, bound on two sides by interstate highways, flanked by bridges, transected by rail lines, and facing onto the Mississippi River. This major confluence of comings and goings plays effectively into the symbolic effect of Saarinen’s “gateway” gesture, but the pedestrian scale of circulation exerts a unique force of its own, guiding the sumptuous and sprawling curves of Dan Kiley’s landscape design to a composition which echoes the flowing form of The Arch itself. The layout derives foremost from the straightforward conditions of axial relation to The Arch and connection to major perimeter entrances, but in resolving these basic requirements, the landscape takes on an organic exuberance, stretching like sinew in the irregular curvature of its forms and elasticity of space. 

Saarinen’s penchant for stainless steel took a number of forms in his early work, expressing high technology in the rolling skin of his 1945 Unfolding House, and high precision with the welded surface of the 1955 GM Styling Dome. The Gateway Arch exhibits both such attributes, but the most relevant value to Saarinen’s choice lay in the longevity of its epochal character: “I was trying to reach for an absolutely permanent form - a high form. Stainless steel would seem to be the most permanent of the materials we have” (Temko 19). 

Originally proposing to build a “Pantheon in lacework” reflecting Jefferson’s own classical interests, Saarinen decided a different form was needed to thrust vertically against the width of the levee (Temko 18). Modeled after catenary curvature for the appearance of strength, but tapered to a more complex profile for the realities of performance, The Arch synthesizes aesthetics and structure with the unimpeded and absolute conviction of true sculpture. Bookending Saarinen’s career as both his first major commission and final posthumous work, The Arch represents a lucid manifesto of his progress towards a new artistic order.

The City of St. Louis traces its origins to a 1764 French settlement, located on the grounds which now host Gateway Arch National Park. While an 1849 fire destroyed the last of its 18th century heritage, the Riverfront district was still among St. Louis’ most historic neighborhoods when it was leveled in the late 1930s, anticipating construction of the Jefferson National Expansion Memorial. Project progenitor Luther Ely Smith was also responsible for bringing urban planner Harland Bartholomew to the city, whose 1947 “Comprehensive Plan for St. Louis” established the framework for postwar urban renewal in the area. Bartholomew’s plan saw the forced displacement of thousands of families, largely African American, throughout the city, and reshaped zoning practices to effectively support the city’s segregation policy. 

When the Gateway Arch officially opened in the late 1960s, the city was suffering the consequences of its newly fragmented urban fabric. The park raised hopes that, along with the new Busch Stadium and Mayor Alfonso Cervantes’ acquisition of the 1964 World’s Fair Spanish Pavilion, Downtown St. Louis could see a commercial and cultural renaissance. While the Spanish Pavilion closed within a year of its relocation, and Edward Durell Stone’s original Busch Stadium has since been replaced, the Gateway Arch was quickly cemented as the city’s most prominent cultural landmark, and remains a leading generator of tourism in the 21st century. 

Two decades after a competition brought Eliel Saarinen to reinvent himself in the United States, the competition for St. Louis’ Expansion Memorial brought a young Eero Saarinen to break with his father’s practice and forge his own direction in architecture. The interpretive challenge of commemoration gave Saarinen the freedom to create a premier expression of the modern age, and the responsibility to honor his young nation with a gesture worthy of the ancient world. Although the more reductive Westward Expansion mythos has rightly been left in the past, Gateway Arch National Park endures as a living icon of American identity and the modern spirit. 

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“Engineering of Saarinen’s Arch.” Architectural Record, May. 1963, pp. 188–191.

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