Greenwich Township was first formed on March 1, 1695, and was formally incorporated as one of New Jersey's initial group of 104 townships by an act of the New Jersey Legislature on February 21, 1798. Over the centuries, portions of the township were taken to form Woolwich Township (March 7, 1767), Franklin Township (January 27, 1820), Spicer Township (March 13, 1844; now Harrison Township), Mantua Township (February 23, 1853), East Greenwich Township (February 10, 1881) and Paulsboro (March 2, 1904). The township was named for Greenwich, England.