Plainfield is a city in Union County, in the U.S. state of New Jersey. Nicknamed "The Queen City", it serves as both a regional hub for Central New Jersey and a bedroom suburb of the New York Metropolitan area, located in the Raritan Valley region. As of the 2020 United States census, the city's population, majority Latino for the first time, was 54,586. This was an increase of 4,778 (+9.6%) from the 2010 census count of 49,808, which in turn reflected an increase of 1,979 (+4.1%) from the 47,829 counted in the 2000 census. In 2022, the Census Bureau estimated the city's population to be 54,513. The area of present-day Plainfield was originally formed as Plainfield Township, a township that was created on April 5, 1847, from portions of Westfield Township, while the area was still part of Essex County. On March 19, 1857, Plainfield Township became part of the newly created Union County. Plainfield was incorporated as a city by an act of the New Jersey Legislature on April 21, 1869, from portions of Plainfield Township, based on the results of a referendum held that same day. The city and township coexisted until March 6, 1878, when Plainfield Township was dissolved and parts were absorbed by Plainfield city, with the remainder becoming Fanwood Township (now known as Scotch Plains). The name "Plainfield", also used in both North Plainfield and South Plainfield, is derived from a local estate or from its scenic location.