U.S. Post Office -- Loop Station, Chicago, IL

U.S. Post Office Loop Station, Chicago, IL


In 1960, Congress authorized the U.S. General Services Administration to construct a new office complex in Chicago's Loop District. The Federal Center consolidated over thirty agencies formerly scattered throughout the city in substandard leased space. Four Chicago architectural firms joined forces for the commission. The world-renowned architect Ludwig Mies van der Rohe (1886-1969) served as the chief designer with Schmidt, Garden and Erikson; C. F. Murphy Associates; and A. Epstein and Sons all working on the project.

German-born Mies was a pioneer of Modern architecture and the last director of the influential Bauhaus school, which operated in Germany from 1919 to 1933. He utilized new materials and technology, most notably industrial steel and plate glass to create austere yet elegant buildings. Calling his buildings "skin and bones architecture," he was well-known for his maxims, "less is more" and "God is in the details."

The original plan for the Chicago Federal Center called for two towers. The first was to house federal agencies including the U.S. Department of the Treasury and U.S. Department of Defense. The second was for the courts, U.S. Department of Justice, and U.S. Postal Service. However, vehicular access for the post office required a street-level loading dock that would have intruded on the openness of the plaza between the two buildings. Upon further study, Mies designed a separate post office building with its own, below-grade vehicular access.

The site for the new Federal Center included the block occupied by the Beaux-Arts style U.S. Post Office and Courthouse (1898-1905) designed by Henry Ives Cobb, which replaced an 1879 government building in the same location. It was in Cobb's domed building where Al Capone was tried for tax evasion in 1917.

Tenants occupied the new U.S. Courthouse, the first of the complex's three buildings to be completed, in 1964. The government began demolition of the old post office in 1965 to clear the site for the two remaining buildings. The Loop Station Post Office and new Federal Building were completed in 1973 and 1974 respectively. The courthouse was renamed for Everett M. Dirksen to honor the longtime Illinois Senator after his death in 1969. The Federal Building was renamed in 1975 to honor John C. Kluczynski, U.S. Representative from Illinois from 1951 until his death in 1975.


The simple and well-proportioned steel-and-glass design of the Chicago Federal Center epitomizes the minimalist architectural approach favored by its architect, Ludwig Mies van der Rohe. Considered one of the greatest architects of the twentieth century, Mies is best known for such projects as the master plan and buildings at the Illinois Institute of Technology (1942-58), Farnsworth House in Plano, Illinois (1946-51), Lake Shore Drive Apartments in Chicago (1948-51), and Seagram Building in New York (1957-59). Works such as these helped bring the International Style, for which Mies was famous, to the forefront of American architecture. Highly geometric and devoid of extraneous ornament, Mies's designs are elegant in their simplicity and illustrate his mastery of spatial composition.

The Federal Center extends over two blocks; a one-block site, bounded by Jackson, Clark, Adams, and Dearborn streets, contains the John C. Kluczynski Federal Building and U.S. Post Office Loop Station, while a parcel on an adjacent block to the east contains the Everett M. Dirksen U.S. Courthouse. A glass-enclosed great hall, 100 feet wide and 25 feet high, spans the center of the courthouse, serving as a visual gateway through the complex. From State Street on the east, one can look west down Quincy Street, through the courthouse, across Dearborn Street to the central plaza and post office beyond.

The structural framing of the buildings is formed of high-tensile bolted steel and concrete. The exterior curtain walls are defined by projecting steel I-beam mullions covered with flat black graphite paint, characteristic of Mies's designs. The balance of the curtain walls are of bronze-tinted glass panes, framed in shiny aluminum, and separated by steel spandrels, also covered with flat black graphite paint. This organization emphasizes the impressive height of the sleek towers. Franz Schulze, a scholar of Mies's work, has praised "Mies's uncompromising devotion to principle, together with his vaunted sensitivity to proportion and structural detail and the organizational scale, [that] combine to give the complex a monumental urban presence." The entire complex is organized on a 28-foot grid pattern subdivided into six 4-foot, 8-inch modules. This pattern extends from the granite-paved plaza into the ground-floor lobbies of the two towers, where the floors and elevator lobby walls are also granite. The lines of the grid continue vertically up the buildings, integrating each component of the complex.

The 42-story, John C. Kluczynski Federal Building is the tallest of the three buildings. It has a total of 1.2 million gross square feet of space, and rises 562 feet above grade with three basements below grade. Both the Kluczynski and Dirksen buildings are elevated on open colonnades, called pilotis, at the plaza level.

To its northwest is the freestanding Loop Station post office, which is one story with two workroom levels below grade. Directly across the street from the Kluczynski building is the thirty-story Everett M. Dirksen U.S. Courthouse. The courthouse contains 1.4 million gross square feet of space and is set at a right angle to the Federal Building high-rise across Dearborn Street. The Dirksen courthouse was designed with fifteen, two-story courtrooms located on the top ten stories of the building. Courtrooms were located away from the curtain walls to reduce audio and visual distractions. The simple but elegant book-matched black-walnut paneling and molded-plywood spectator benches are lit by ceiling fixtures covered with an aluminum grid. During the 1990s, additional courtrooms were created within the building in a style complimenting the original details; Mies's initial design planned for future expansion of this nature.

In the early 1970s, the U.S. General Services Administration, under its Art in Architecture program, commissioned a steel sculpture for the plaza from the celebrated artist Alexander Calder. His creation, entitled Flamingo, was unveiled on October 25, 1974. The 53-foot-tall steel stabile, with its bright red color and graceful curves, provides a striking contrast to the dark, angular steel and glass curtain walls of the Federal Center buildings. In 1998, the stabile was conserved and lighting was added.

Significant Events

1960: Congress authorizes the construction of the Chicago Federal Center

1964: U.S. Courthouse completed

1965-1966: 1905 federal building demolished to allow for the construction of remaining two buildings

1973: U.S. Post Office Loop Station completed at Federal Center's northwest corner

1974: Federal Building completed; Flamingo stabile by Alexander Calder installed in plaza

1993-1999: Additional two-story courtrooms constructed within original structure of Dirksen U.S. Courthouse

2002: Installation of perimeter-security bollard system in response to increased security requirements for federal properties

2006: Exterior curtain wall repair and repainting of entire three structure complex with Miesian black paint

Building Facts

Architects: Ludwig Mies van der Rohe; Schmidt, Garden and Erikson; C. F. Murphy Associates; A. Epstein and Sons

Construction Dates: 1960-1974

Location: Dearborn Street between Jackson Boulevard and Adams Street in downtown Chicago's central Loop

Architectural Style: International Style

Primary Materials: Steel and bronze-tinted glass; granite paving

Prominent Features: Striking glass tower; Projecting steel I-beam mullions; Open colonnades at tower bases; Flamingo stabile

U.S. Post Office Loop Station, Chicago, IL

1.4 Architectural Description

Designed in 1965 and finally completed in 1973, the United States Post Office Loop Station has changed little since its construction and still retains its original architectural features and configuration. It is a one-story building that rises 27 feet above grade. The footprint measures 332 square feet and has a total square footage of over 100,000 gross square feet. The structural system is arranged on a grid of 28 square feet with a vertical floor to ceiling height of 24 feet.

The building’s structural system is steel frame construction. There are nine structural bays with four interior columns. The exterior is painted steel with plate glass infill. The large plate glass windows dominate the facade of the building making it appear light and transparent. Only the columns and steel fascia at the top of the building appear to be solid elements. Each structural bay is divided into seven glazing bays. Each glazing bay is divided vertically with eight foot high windows on the bottom and sixteen foot high windows above. The lower windows are in turn divided vertically in two sections. All steel was originally painted with a flat black graphite paint. Although the building has been repainted, the exterior steel still retains its original dark black appearance.

There are entries on the east and west sides of the building, though the primary entry is on the east side through the main plaza. The east entry leads into the main lobby with postal service counters directly across from the entry. The interior has an open appearance overall, though the center section is enclosed with walnut veneered wood panel partitions. The partitions do not engage the ceiling, thus providing the sense of openness and flexibility of a typical Miesian universal space. The partitions hide postal operations and services while the public lobby extends around the perimeter of the building. Behind the main service counters is an elevator and mechanical core clad in dark green granite that rises to the ceiling, the only feature in the building to do so.

Interior flooring is gray Rockville granite, which is the same as found on the plaza, and carries throughout the public spaces of the main lobby. The ceiling is plaster, painted white, with recessed downlights. The walls of the central core are veneered with walnut panels similar to partitions found in other Mies buildings. The partitions extend beyond the corners to create the effect of wall planes sliding past one another, which was typical in other works by Mies. The service counters are faced with dark green granite with tinted glass panels. Free standing writing counters of chromed steel legs and the same green granite of the service counters are placed throughout the lobby.

On the west end of the building are the post office boxes. These are set behind a wall and feature walnut paneled walls above and Rockville granite walls surrounding the aluminum framed boxes. The ceiling is a luminous grid with fluorescent lighting.

The lower levels are devoted to truck docks and mail sorting. These spaces are primarily utilitarian and contain little architectural significance although they do retain much of their integrity. The basement levels, from lowest up, include the Platform Level, Workroom Level and Workroom Mezzanine Level. The truck docks are accessed by a ramp located south of the post office between it and the federal office building and lead to a loading dock on the Platform Level.


Mies van der Rohe

Ludwig Mies van der Rohe was born in Aachen, Germany in 1886. His father was a master mason, a career in which Mies intended to pursue as well. As a young man, he briefly worked as an apprentice in the trade, but soon moved to a number of different drafting jobs with local architectural offices. To advance his architectural career further, Mies moved to Berlin in 1905 to work for architect Bruno Paul. Three years later he began working for Peter Behrens, a well known German architect and mentor to other celebrated modern architects such as Walter Gropius and Le Corbusier. In 1912, Mies left Behrens office and began to pursue a solo career. He worked mostly on small residential projects and his early works were significantly influenced by the architecture of Behrens. Mies’ work began to take on a more modern appearance following World War I and quickly developed into the modern architectural aesthetic he is most famous for. In 1926, his career was further elevated when he was asked to direct the design of the Deutscher Werkbund’s Weissenhofsiedlung housing exposition in Stuttgart. Mies designed the site plan and one of the buildings for the project which also included designs by Le Corbusier, Walter Gropius, Peter Behrens, and Bruno Taut.

In 1930, Mies was appointed director of the avant-garde Bauhaus in Dessau, Germany. The school, which was founded by Gropius in 1919, became a nucleus for modernist design in Europe in the 1920s. However, by the time Mies took over, the Nazi party was becoming more powerful in Germany and its more conservative policies were at odds with the more freethinking, liberal agenda of the Bauhaus. Mies was forced to close the school in 1932 when the Nazis took over the city of Dessau.

With the Nazi party on the rise in Germany, Mies was eventually forced to leave. He accepted a position as the head of the architecture department at the Armour Institute of Technology (later renamed the Illinois Institute of Technology) in 1938. In Chicago, Mies was able to practice his modernist architecture freely. He cultivated a new curriculum at the school and used the architecture studios to experiment with and develop his design concepts. From the studios, Mies developed the concepts of the clear span building and universal space. He also developed a master plan for the Illinois Institute of Technology (IIT) campus and designed twenty of the university’s new buildings.

While directing the architecture program at IIT, Mies also developed a private architectural practice. In his private practice, his ideas and concepts were developed and in in his studio, they came to fruition. His designs for the Farnsworth House in Plano, Illinois as well as S. R. Crown Hall on the IIT campus were developed out of his concept of universal space. In addition to smaller low rise buildings, he also designed skyscrapers. His skyscrapers were designed so the structural system was fully expressed on the exterior and utilized his two favorite building materials: steel and glass. Two of his most well known projects that took advantage of this system include the apartment towers 860 and 880 Lake Shore Drive in Chicago and the Seagram Building in New York. The Seagram Building also included a public plaza, a concept which Mies would further develop and utilize in later designs, including the Chicago Federal Center.

The Chicago Federal Center was one of the largest projects Mies’ office worked on and became a significant challenge in urban design. In addition to his design for the Chicago Federal Center, Mies completed other large urban planning projects, including the Lafayette Park Housing Project in Detroit and the Toronto Dominion Centre. The Toronto Dominion Centre closely resembles the Chicago Federal Center in its layout and architectural design. Both projects were in the office at roughly the same time and both were laid out on a grid with an asymmetrical massing of buildings surrounding a central plaza.

Mies continued to teach and practice until his retirement from IIT in 1958. Following his retirement from teaching, he continued to stay involved with his architectural practice. Many of his students at IIT went on to work for him and for other well respected architecture firms in Chicago and throughout the country. He also influenced the work of many other architectural practices of the time including Skidmore, Owings and Merrill (SOM) and C. F. Murphy and Associates. When Mies died in 1969, his firm continued as the Office of Mies van der Rohe under the leadership of his trusted associates Joseph Fujikawa, Bruno Conterato, and his grandson Dirk Lohan. In 1975, the partners changed the name to Fujikawa, Conterato, Lohan and Associates.

Mies van der Rohe was the lead designer for the Federal Center project and his office was responsible for all phases of design. Mies himself was involved with the project and had the final say on all design decisions; however, the project was led initially by his associate Gene Summers until he left in 1965. After that, the project was led by Bruno Conterato.

C.F. Murphy and Associates

C.F. Murphy and Associates was founded in 1937 as Shaw, Naess and Murphy. Its original owners and principals included Charles Francis Murphy, Alfred Shaw and Sigurd Naess. The three partners had previously worked together at Graham, Anderson, Probst and White and were close associates of Ernest Graham. When Graham died in 1936, the three were fired and joined together to form the new firm. In the 1940s, Shaw left the firm and the name was changed to Naess and Murphy. Charles F. Murphy never had professional training as an architect; however, he had apprenticed under Ernest Graham and was an excellent businessman. The success of the firm was primarily due to Murphy’s business expertise and extensive list of client contacts. In 1957, Naess retired and the firm changed its name to C.F. Murphy and Associates a few years later.
The firm’s first major project was the Prudential Building in 1955, which at the time was the tallest building in Chicago. Because of Murphy’s close relationship with Chicago Mayor Richard J. Daley, C. F. Murphy and Associates was able to work on a number of major public building projects including planning and design of the terminals for O’Hare International Airport, the McCormick Center, the Chicago Civic Center (now Richard J. Daley Center), and the Chicago Federal Center. The firm also designed the First National Bank Building (now the Chase Building) in a joint venture with Perkins and Will. C.F. Murphy continued to be successful throughout the 1960s and 70s with the help of talented architects such as Gene Summers and Helmut Jahn. In 1981, the firm changed its name to Murphy/Jahn when Helmut Jahn became a partner in the firm. Jahn became sole owner of the firm when Charles Murphy died in 1985.

For the Chicago Federal Center project, C.F. Murphy Associates was primarily responsible for architectural detailing and planning. They did not, however, lead the overall design of the project, which was conducted by the Office of Mies van der Rohe.

Schmidt, Garden, and Erikson

Schmidt, Garden, and Erikson dates back to 1901, when Richard Ernest Schmidt joined together with Hugh Mackie Gordon Garden to form the firm of Schmidt and Garden. Before forming their partnership, Garden had previously worked for such notable Chicago architects as Sheply, Rutan and Coolidge, Howard Van Doren Shaw, Henry Ives Cobb, and Frank Lloyd Wright. Schmidt had also established his reputation in Chicago by the 1890s as a talented residential designer. Schmidt and Garden’s early work included the original building of Michael Reese Hospital and the Administration and Powerhouse buildings of the Schoenhofen Brewery in Chicago. The firm changed its name to Schmidt Garden and Martin in 1906 when the talented structural engineer Edgar Martin joined the firm as its newest partner. In 1925, Edgar Martin was replaced by longtime employee Carl A. Erikson and the firm became known as Schmidt, Garden, and Erikson. In later years, the firm designed five campus buildings for the Illinois Institute of Technology, all of which were designed to follow the Miesian aesthetic and master campus plan.

The firm of Schmidt, Garden, and Erikson was primarily responsible for the mechanical engineering for the John C. Kluczynski Federal Building and the rest of Federal Center complex.

A. Epstein and Sons

A. Epstein and Sons was founded in 1921 by structural engineer Abraham Epstein. The firm’s name was changed to A. Epstein and Sons when Abraham’s two sons, Raymond and Sidney, joined the firm. Although founded as an engineering firm, Epstein and Sons expanded its scope over time to include architecture, especially that of industrial buildings and warehouses. Some of their early work included projects at the Central Manufacturing District and the Union Stockyards in Chicago. Because of its engineering expertise, the firm collaborated on numerous high profile projects in the post-War years including the Chicago Federal Center project. In the 1950s, the firm became one of the first to do design/build work, in which the firm was responsible for both the design and construction of a building. A. Epstein and Sons still remains in Chicago today as an architecture/engineering firm.

A. Epstein and Sons was primarily responsible for the structural and electrical engineering work on the Chicago Federal Center.

Alterations and Current State

Alterations to the U.S. Post Office Loop Station have been minimal. Storefront glazing was replaced in 1994, a new handicap entrance was added on the west side in 2002, and the entire exterior of the building was rehabilitated in 2005. This work included replacing glazing sealant and repainting the steel with a coating system that closely matches the original flat black color. There have been minimal alterations in the main lobby. Most of the changes have occurred in work and support spaces that are not architecturally significant and not accessible to the public.

The post office has been well maintained since its construction and rehabilitation efforts have kept the building in relatively the same condition as it was when first constructed. The building retains all of its significant architectural features and stays true to Mies’ original design intent.

U.S. Post Office Loop Station, Chicago, IL

2.1 Integrity and Significance

An assessment of the historic integrity of exterior and interior spaces and elements at the Loop Post Office (LPO) was conducted as part of this report. The assessment was conducted by comparing original design drawings, historic photographs and the existing conditions in order to identify each space’s level of architectural significance and historic integrity. As part of the assessment of the existing conditions, a cursory survey was conducted of the exterior and interior spaces. Based on the building assessment, the LPO was divided into different preservation zones based on the relative historic and architectural significance and integrity within each area of the building.

The exterior and interior spaces and/or elements will be categorized as being either in the Restoration, Rehabilitation or Renovation Zone. The criteria for each of the Zones has been established by GSA and is outlined in Attachment 3: Guidelines for Zoning Historic Buildings. They will also be summarized before the Zoning drawings. In general, all portions of the building’s exterior and site are of primary significance and are classified in the Restoration Zone. Original spaces and elements in primarily public locations that have high architectural significance will typically be categorized in the Restoration Zone. Elements/spaces in semi-public or private spaces that are original and moderately architecturally significant will be considered in the Rehabilitation Zone. Spaces not fitting in the above two categories will be classified in the Renovation Zone.

The analysis of the Restoration spaces will be subdivided by element (i.e. flooring, walls, etc.) and further subdivided into “description”, “condition”, and “recommendations” for spaces in Zone 1: Restoration Zone. This information will be general however, given that only a cursory survey of the spaces was performed. The basement levels will be treated less specifically given that there are numerous spaces which have similar treatments which are typically non-public service and workspaces.

The following zones have been identified:

Zone 1: Restoration Zone
1A Exterior -- Plaza and Surrounding Site
1B Exterior – Building Facades
1C Exterior – Roof
1D Interior – Main Lobby & Post Office Box Area
1E Interior – Stairs from Workroom Mezzanine to Main Lobby

Zone 2: Rehabilitation Zone:
2A Interior -- First floor workspaces including the central work area, registry room, vaults, toilet rooms, and janitor’s closets
2B Interior -- Platform, Workroom and Workroom Mezzanine Level:
Workrooms, Carrier Call Room, Toilet Rooms, Janitor’s Closets, Platform Level Loading Dock Masonry Walls, Offices, Storage Rooms

Zone 3: Renovation Zone
3A Interior -- First floor Workspaces including Offices, Conference Room, Ancillary and Storage Rooms, Closets, Mechanical rooms, and Elevators
3B Interior -- Platform, Workroom and Workroom Mezzanine Level: Locker Rooms, Mechanical Rooms, Workroom Mezzanine Public Corridors, Platform Level Maneuvering Area, Workroom Level Parking Area, Lookout Spaces, Mechanical/Electrical Rooms, Emergency Egress Stairs

Description Architect
1966 1973 Joint venture Mies van der Rohe
1966 1973 Joint venture C. F. Murphy and Associates
1966 1973 Joint venture Schmidt, Garden, and Erikson
1966 1973 Joint venture A. Epstein and Son
Last Reviewed: 2017-08-13