Linden is a city in southeastern Union County, New Jersey, United States. It is part of the New York Metropolitan Area, located about 13 miles southwest of Manhattan and bordering Staten Island, a borough of New York City, across the Arthur Kill. As of the 2010 United States Census, the city's population was 40,499, reflecting an increase of 1,105 from the 39,394 counted in the 2000 Census, which had in turn increased by 2,693 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, Linden Borough and Roselle. 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, based on the results of a referendum held on November 8, 1923. The city's name derives from linden trees brought from Germany.