One of Frederick Law Olmsted’s greatest accomplishments is the U.S. Capitol Grounds in Washington, D.C. The 58-acre park was landscaped by Olmsted in an expansive project that was performed from 1874 to 1892. In describing his plan for the U.S. Capitol Grounds, Olmsted noted that “the ground is in design part of the U.S. Capitol, but in all respects subsidiary to the central structure.” He wanted his design to complement and highlight the U.S. Capitol Building and created a natural landscape that incorporated park-like edging, low walls, lamps, careful placement of trees and shrubs, and a series of curved walkways that offer attractive views of the U.S. Capitol but do not distract the viewer from the building.
Trees were heavily used in Olmsted’s design to both frame the building and provide shade for visitors. There are about 890 trees surrounding the immediate U.S. Capitol Building and more than 4,200 trees throughout the entire 274-acres of grounds. Currently there are over 100 varieties of trees and bushes planted around the U.S. Capitol Grounds and many of the trees have historic or memorial associations. In addition, more than 30 states have made symbolic gifts of their state trees to the grounds. Many of the trees on the grounds bear plaques that identify their species and their historic significance, such as the cherry trees given by Japan in 1912 or the horse chestnut tree dedicated to Anne Frank in 2014.
Olmsted was careful not to group trees or other landscape features in any way that would distract the viewer from the U.S. Capitol, therefore the use of sculpture and other ornamentation was kept to a minimum. The northern part of the grounds offers a shaded walk among trees, flowers and shrubbery that leads to a small, hexagonal brick structure, named the Summerhouse. It was included in Olmsted’s design in response to complaints that visitors to the U.S. Capitol could not find water or a place to rest on their journey. Olmsted originally planned two Summerhouses for the U.S. Capitol Grounds (references in two of his letters identify a northern and a southern Summerhouse); however, congressional objections to the northern Summerhouse before its completion prevented the construction of the southern one.
Much of Olmsted’s landscape legacy is architectural rather than horticultural and landscape architects coined the term “hardscape” to distinguish these elements. Hardscape elements in Olmsted’s design include the terraces of the Capitol itself, low walls bordering the walks and roads, and the various lamps needed for lighting the grounds at night. Some of Olmsted’s significant hardscape elements are two large rectangular fountains that can be found on the East Front Plaza of the U.S. Capitol. The bottom levels now contain plantings, but in the past, they have been used to catch the spillover from the fountains. The fountains and lanterns are fully modernized, and new technologies, such as the fountain’s water pressure levels, are tied to an anemometer that lowers the water pressure as winds rise.
More than 140 years later, Olmsted’s design still drives all landscaping decisions on the U.S. Capitol Grounds. The placement and selection of new trees and the restoration and modernization work completed as part of the building of the Capitol Visitor Center support this urban oasis in the nation’s capital for visitors from all over the world.