Edison is a township in Middlesex County, New Jersey, United States, in the New York City metropolitan area, and the Raritan Bayshore subregion of the Jersey Shore. As of the 2010 United States Census, Edison had a total population of 99,967, retaining its position as the fifth-most populous municipality in New Jersey. The 2010 population reflected an increase of 2,280 from the 97,687 counted in the 2000 Census, which had in turn increased by 9,007 from the 88,680 counted in 1990. Edison's population has been above the 100,000 threshold since 2010, increasing by 2.7% to a Census-estimated 102,701 in 2015.What is now Edison Township was originally incorporated as Raritan Township by an act of the New Jersey Legislature on March 17, 1870, from portions of both Piscataway Township and Woodbridge Township. Portions of the township were taken to form Metuchen on March 20, 1900, and Highland Park on March 15, 1905.