The United States Capitol is located in a 58-acre park that was landscaped by Frederick Law Olmsted during the period 1874-1892. As additional buildings were added in support of the Capitol, facilities such as the Library of Congress or the congressional office buildings, the Grounds were enlarged as well. Today, the Grounds cover approximately 274 acres.
Originally a wooded wilderness, the U.S. Capitol Grounds now provide a park-like setting for the nation's Capitol Building, offering a picturesque counterpoint to the building's formal architecture. The grounds immediately surrounding the U.S. Capitol are bordered by a stone wall and cover an area of 58.8 acres. It’s boundaries are Independence Avenue on the south, Constitution Avenue on the north, First Street NE/SE on the east, and First Street NW/SW on the west.
Over 100 varieties of trees and bushes are planted around the Capitol, and thousands of flowers are used in seasonal displays. In contrast to the building's straight, neoclassical lines, most of the walkways in the grounds are curved. Benches along the paths offer pleasant spots for visitors to appreciate the building, its landscape, and the surrounding areas, most notably the National Mall to the west.
The grounds were designed by Frederick Law Olmsted (1822-1903), who planned the expansion and landscaping of the area that was performed from 1874 to 1892. Olmsted, who also designed New York's Central Park, is considered the greatest American landscape architect of his day. He was a pioneer in the development of public parks in America, and many of his designs were influenced by his studies of European parks, gardens and estates. In describing his plan for the Capitol Grounds, Olmsted noted that "The ground is in design part of the Capitol, but in all respects subsidiary to the central structure." Therefore, he was careful not to group trees or other landscape features in any way that would distract the viewer from the Capitol Building. The use of sculpture and other ornamentation has also been kept to a minimum.
Many of the trees on the Capitol Grounds have historic or memorial associations. A number commemorate members of Congress and other notable citizens, national organizations and special events. In addition, more than 30 states have made symbolic gifts of their state trees to the Capitol Grounds. Many of the trees on the grounds bear plaques that identify their species and their historic significance. The eastern part of the grounds contains the greatest number of historic and commemorative trees.
At the East Capitol Street entrance to the Capitol Plaza are two large rectangular stone fountains. The bottom levels now contain plantings, but at times in the past they have been used to catch the spillover from the fountains. At other times, both levels have held plantings. Six massive red granite lamp piers topped with light fixtures in wrought-iron cages, and 16 smaller bronze light fixtures, line the paved plaza. Seats are placed at intervals along the sidewalks. Three sets of benches are enclosed with wrought-iron railings and grilles; the roofed bench was originally a shelter for streetcar passengers.
The northern part of the grounds offers a shaded walk among trees, flowers, and shrubbery. A small, hexagonal brick structure named the Summerhouse may be found in the north-west corner of the grounds. This structure contains shaded benches, a central ornamental fountain, and three public drinking fountains. In a small grotto on the eastern side of the Summerhouse, a stream of water flows and splashes over rocks to create a pleasing sound and cool the summer breezes.