Middlesex County

Carteret borough [1906: Roosevelt to 1921]
Cranbury Township [1872]
Dunellen borough [1887]
East Brunswick Township [1860]
Edison Township [1870: Raritan to 1954]
Helmetta borough [1888]
Highland Park borough [1905]
Jamesburg borough [1887]
Metuchen borough [1900]
Middlesex borough [1913]
Milltown borough [1889]
Monroe Township [1838]
NEW BRUNSWICK city [1730]- county courthouse
North Brunswick Township [1779: created through division of New Brunswick Township (1724) into wards, Township status confirmed 1798]
Old Bridge Township [1869: Madison to 1975]
Perth Amboy city [1718]
Piscataway Township [1693]
Plainsboro Township [1919]
Sayreville borough [1876: Township to 1919]
South Amboy city [1782: Township to 1888, borough 1888-1908]
South Brunswick Township [1779: created through division of New Brunswick Township (1724) into wards, Township status confirmed 1798]
South Plainfield borough [1926]
South River borough [1870: Washington town to 1898]
Spotswood borough [1908]
Woodbridge Township [1693]

Source:  New Jersey Localities: Civil Divisions and Municipalities; http://www.thegreenpapers.com/slg/localities.phtml?state=NJ