The present-day political jurisdiction of the City of New York came into existence on January 1, 1898. Before this, New York City consisted of Manhattan Island and a part of Westchester County known as "Morrisania" or the "Annexed District".

With the creation of the City of New York, the municipal limits were extended to take in more of Westchester County, as well as Queens County (including the incorporated Long Island City), the incorporated city of Brooklyn and the entirety of Richmond County / Staten Island.

Five "boroughs" were created; Manhattan, The Bronx, Queens, Brooklyn and Richmond. Manhattan and the Bronx formed New York County. Queens was Queens County, Brooklyn was Kings County and Richmond was Richmond County.

Three eastern towns in Queens / Queens County were incorporated out of the boundaries of the City of New York in 1899. They became Nassau County. In 1914, the borough of The Bronx became Bronx County. Richmond became officially known as the Borough of Staten Island in 1975 (but was still the jurisdiction of Richmond County).