Trenton is the capital city of the U.S. state of New Jersey and the county seat of Mercer County. It briefly served as the capital of the United States in 1784. The city’s metropolitan area, consisting of Mercer County, is grouped with the New York Combined Statistical Area by the United States Census Bureau, but it directly borders the Philadelphia metropolitan area and was from 1990 until 2000 part of the Philadelphia Combined Statistical Area. As of the 2020 United States Census, Trenton had a population of 90,871, making it the state’s 10th-largest municipality in 2010 and 2020, after having been the state’s ninth-largest municipality in 2000. The population in 2020 stood at 90,871, an increase of 5,958 (+7.0%) from the 84,913 reported in the 2010 Census, reversing decades of population loss.
Trenton dates back at least to June 3, 1719, when mention was made of a constable being appointed for Trenton while the area was still part of Hunterdon County. Boundaries were recorded for Trenton Township as of March 2, 1720. A courthouse and jail were constructed in Trenton around 1720, and the Freeholders of Hunterdon County met annually in Trenton.
Trenton received its first Postmaster in 1764. On November 25, 1790, the Trenton became New Jersey’s capital, and by November 13, 1792 the City of Trenton was formed within Trenton Township. Trenton Township was incorporated as one of New Jersey’s initial group of 104 townships by an act of the New Jersey Legislature on February 21, 1798. On February 22, 1834, portions of Trenton Township were taken to form Ewing Township. The remaining portion of Trenton Township was absorbed by the City of Trenton on April 10, 1837. A series of annexations took place over a 50-year period, with the city absorbing South Trenton borough (April 14, 1851), portions of Nottingham Township (April 14, 1856), both the Borough of Chambersburg Township, and Millham Township (both on March 30, 1888), as well as Wilbur Borough (February 28, 1898). Portions of Ewing Township and Hamilton Township were annexed to Trenton on March 23, 1900.