Princeton is a municipality with a borough form of government in Mercer County, New Jersey, United States, that was established on January 1, 2013, through the consolidation of the Borough of Princeton and Princeton Township. As of the 2010 United States Census, the borough's population was 28,572, reflecting the former township's population of 16,265, along with the 12,307 in the former borough.
Although residents of Princeton (Princetonians) traditionally have a strong community-wide identity, the community had been composed of two separate municipalities: a township and a borough. The central borough was completely surrounded by the township. The Borough seceded from the Township in 1894 in a dispute over school taxes; the two municipalities later formed the Princeton Public Schools, and some other public services were conducted together before they were reunited into a single Princeton in January 2013. The Borough contained Nassau Street, the main commercial street, most of the University campus, and incorporated most of the urban area until the postwar suburbanization. Borough and Township had roughly equal populations.