The U.S. Botanic Garden is supervised by the Congress through the Architect of the Capitol, who is responsible for maintaining the grounds of the United States Capitol. The USBG is open every day of the year, including federal holidays. It is the oldest continually operating botanic garden in the United States.
During the late 18th century, George Washington, Thomas Jefferson and James Madison shared the dream of a national botanic garden and were instrumental in establishing one on the National Mall in 1820.
The institution actually traces its beginning to 1816, when the constitution of the Columbian Institute for the Promotion of Arts and Sciences in Washington, D.C., proposed the creation of a botanical garden to collect, grow and distribute plants of this and other countries that might contribute to the welfare of the American people. The Institute's garden was established by Congress in 1820 to the west of the Capitol Grounds, from First Street to Third Street between Pennsylvania and Maryland Avenues. This facility functioned until shortly after the organization stopped holding meetings in 1837.