Trenton is the capital city of the U.S. state of New Jersey and the county seat of Mercer County. It was briefly the capital of the United States. The city's metropolitan area is grouped with the New York metropolitan area by the United States Census Bureau, but directly borders the Philadelphia metropolitan area and is part of the Federal Communications Commission's Philadelphia Designated Market Area. As of the 2010 United States Census, Trenton had a population of 84,913, making it the state's 10th-largest municipality. The Census Bureau estimated that the city's population was 84,034 in 2014.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.