The District of Columbia Organic Act of 1871 aka “An Act to provide a Government for the District of Columbia (41st Congress, 3d Sess., ch. 62, 16 Stat. 419, enacted 1871-02-21) is an Act of Congress, which revoked the individual charters of the City of Washington, the City of Georgetown, and the County of Washington and created a new city government for the entire District of Columbia. The legislation effectively merged what had been separate municipalities within the federal territory into a single entity. It is for this reason that the city, while legally named the District of Columbia, is still commonly known as Washington, D.C. However, this act was abolished in 1874, and while the name did not change, the territorial Governor was replaced with a three-member Board of Commissioners appointed by the President. This system existed until 1974 when the District of Columbia Home Rule Act allowed for District residents to elect their own mayor.
Below is the text of the bill: