The Federal Building occupies the entire block bound by Congress Parkway and Harrison, Clark, and LaSalle Streets in downtown Chicago. The building abuts concrete sidewalks on three sides, and elevated train tracks pass parallel to the Lasalle Street elevation. The Congress Parkway elevation was originally a party wall, but was exposed when the adjacent building was demolished. This elevation also breaks with the rectilinear shape of the building. Today there is a small parking area and paved plaza with trees on the adjacent lot, as well as surface access to a subway station. Vehicular access to the interior courtyard is available on this elevation. The building measures approximately 299' by 216', and is 10-stories in height. There is a large (68' by 128') courtyard in the middle of the rectangular building to bring daylight into the core offices. The building structure is a steel-reinforced cast-concrete frame. The primary elevations face Clark and Harrison Streets, are clad with brick and terra cotta and have the few decorative elements on an otherwise plain building. The secondary elevations face LaSalle Street and Congress Parkway, and vary in appearance with one being clad in brick and the other having a cement plaster finish, respectively. These elevations are devoid of most detail. The expansive roof is flat and has various mechanical equipment, elevator penthouses, and communications equipment. The Clark Street Facade (East) is 18 bays wide, and contains the primary building entry. This entry is distinguished with a decorative 2-story recessed vestibule with Gothic style detailing, and is completely clad in terra cotta. Each bay us defined by brick pilasters, and contains two windows. Each pilaster has a cap above the second floor and at the parapet. The windows at the first and second floor have molded terra cotta sills and lintels. Windows above have simple stone sills and lintels. Each bay is crowned above the 10th floor windows by an arch of stone, terra cota, and brick details. Centered on the prophet above each bay is a round decorative terra cotta medallion. The corner bays have similar medallions that are rectilinear in shape and have different iconography. The corner bays are further distinguished with a stepped parapet. The Harrison Street elevation (South) is similar to the Clark Street elevation, except it is less detailed an dis 10 bays wide. Terra cotta is limited to the sidewalk- level infill beneath the first floor windows. Each bay contains three windows, and the pilasters are treated similar to those on Clark Street. This elevation also continues the arch details at the parapet, as well as the medallions and corner treatments found on Clark Street. The sidewalk slopes down towards the northwest corner, which is level with the street. The LaSalle Street Elevation is similar to both the Clark and Harrison Street elevations, but omits the terra cotta blocks at the watertable. There is a former public entry on the west elevation, which is only distinguished by the recessed doors and a wider bay. There were flag poles mounted at each pilaster, however, these were removed when the entry was shifted north to serve a single tenant. The Congress Parkway elevation is the plainest of all elevations, probably because it was not intended to be exposed. The north-facing elevation has a portion just under half of its width that projects from the face by two bays, and was formerly a party wall. The west half consist of 15 bays of punched window openings that continue around the west face of the building projection. The former party wall has punched window openings that form an inverted T, and begins at the fourth floor. This elevation is otherwise devoid of detail, and is covered with a painted cement plaster finish. There is a large opening at street level approximately centered on the elevation that provides vehicular access to the interior courtyard. The interior courtyard is simple in detail, and four, stepped mechanical shafts dominate the courtyard, one in each corner. These shafts are approximately one bay wide, and are covered with painted corrugated sheet metal panels. Window locations approximately mirror those corresponding on the street elevations, and there are several openings that have been altered or removed. The windows also vary in size and condition more on the street elevations. There are a few original wood one-over-one units intact on these elevations. The windows are replacement anodized aluminum units that vary in appearance, but are most commonly fixed one-over-one units with unequal portions. Many windows in the courtyard have obscured glazing in the upper portion. Window infill varies around the building and in the courtyard, and include recessed brick panels, glass block and metal louver units. Toilet room window in the courtyard have obscure glazing. The exterior doors are replacement aluminum storefront systems, some with transom lights above. Doors in the courtyard are automatic, and there is a revolving door at the Clark Street entry. There is a pair of motorized swinging iron gates at the vehicle courtyard entrance, as well as a coiling security system. The interior of the building has mostly altered throughout to accommodate various tenant offices. In the course of these renovation most historic fabric was removed, and any original open plans have been partitioned for offices. The most intact interior spaces are the east and west lobbies. The east lobby is far more detailed and finished than the west lobby, and includes marble veneer and stairs, terazzo floor surfaces,a coffered plaster ceiling and aluminum elevator doors. This lobby also opens to the second floor with a mezzanine. The west lobby has historic finishes, but is more restrained. Typical materials in include terazzo floor surface, marble base and wainscot and plaster walls. The ceiling has been lowered with an acoustical ceiling tile grid. In addition, there is one set of toilet rooms that retain some historic fabric. Finally the elevator lobbies and adjacent interior stairs appear to be original in their configuration, but have been altered and are not architecturally significant. Generally the floor plan consist of private offices and building services accessed off of a double loaded corridor that circles the floor. The plan is usually consistent throughout the building, however, the corridor placement and configuration does vary on some levels. Some tenants have large open office aras with systems furniture. Typical finishes in the tenant spaces include carpet tile, vinyl composition tile, rubber base trip and suspended acoustical tile ceilings. The laboratory spaces on the tenth floor of the building have fluid-applied floor coatings, and there are limited areas of painted concrete and quarry tile floors in the basement. Historic glazed brick wainscot occurs in limed portions of the basement boiler rooms as well. Typical toilet rooms have modern ceramic tile wall and floor surfaces; framing with painted gypsum wallboard, however there are rooms with concrete masonry wall structure as well. Various areas have partitioned walls formed by a pointed metal panel system that date to 1950's and 1960's office renovations by the government.