For sites of same name, see: Union City. Note that Union City is not in Union County, New Jersey. Union City is a city in Hudson County, New Jersey, United States. According to the United States 2000 Census, the city had a total population of 80,589, living on a land area of 3.28 km² (1.27 sq mi). It is the most densely populated city in the United States and in the Americas, with a density of 52,977.8 per square mile. Union City was incorporated as a city by an Act of the New Jersey Legislature on January 1, 1925, with the merger of Union Hill and West Hoboken Township. Two major waves of immigration, first of German-language speakers and then of Spanish-language speakers, greatly influenced the development and character of Union City. Its two nicknames, "Embroidery Capital of the United States" and "Havana on the Hudson", reflect important aspects of that history. Thousands make a pilgrimage to Union City each year to see the nation's longest running passion play.