Linden is a city in southeastern Union County, New Jersey, United States. It is part of the New York Metropolitan Area, being about 13 miles (21 km) southwest of Manhattan, and bordering Staten Island, a borough of New York City. As of the 2010 United States Census, the city's population was 40,499, reflecting an increase of 1,105 (+2.8%) from the 39,394 counted in the 2000 Census, which had in turn increased by 2,693 (+7.3%) from the 36,701 counted in the 1990 Census.
Linden was originally formed as a township on March 4, 1861, from portions of Elizabeth, Rahway and Union Township. Portions of the township were taken to form Cranford (March 14, 1871), Linden Borough (March 30, 1882) and Roselle (December 20, 1894). Linden was incorporated as a city by an Act of the New Jersey Legislature on January 1, 1925, replacing both Linden Township and Linden Borough (which had been formed in 1882 from the township), based on the results of a referendum held on November 8, 1923.