Jersey City is the seat of Hudson County, New Jersey, United States. As of the 2010 United States Census, the population of Jersey City was 247,597, making it the second-most populous city in New Jersey.
Part of the New York City metropolitan area, Jersey City lies across from Lower Manhattan between the Hudson River and Upper New York Bay and the Hackensack River and Newark Bay. A port of entry, with 11 miles (18 km) of waterfront and significant rail connections, Jersey City is an important transportation terminus and distribution and manufacturing center for the Port of New York and New Jersey. Service industries have played a prominent role in the redevelopment of its waterfront and the creation of one of the nation's largest downtowns.
After a peak population of 316,715 measured in the 1930 Census, the city's population saw a half-century long decline to a low of 223,532 in the 1980 Census, but since then the city's population has grown, with the 2010 population reflecting an increase of 7,542 (+3.1%) from the 240,055 counted in the 2000 Census, which had in turn increased by 11,518 (+5.0%) from the 228,537 counted in the 1990 Census.