Upper Freehold Township dates back to 1731, when it was formed from portions of Freehold Township. It was formally incorporated as a township by the Township Act of 1798 of the New Jersey Legislature on February 21, 1798. Over the years, portions of the township have been taken to form Millstone Township (February 28, 1844), Jackson Township (March 6, 1844) and Allentown (January 20, 1889).[18] The name of the township derives from Freehold Township, which in turn is derived from the word freehold, an English legal term describing fee simple property ownership.[19]

What is now Green Brook was originally created as North Plainfield Township on April 2, 1872, from portions of Warren Township. Portions of the township were taken to form North Plainfield borough (June 9, 1885) and Watchung (March 23, 1926). Green Brook was incorporated as a township by an act of the New Jersey Legislature on November 8, 1932, replacing North Plainfield Township, based on the results of a referendum held that same day.[1][21]

What is now Emerson was originally formed on April 8, 1903, from portions of Washington Township as the Borough of Etna, the name of a railroad station in the community.[22] The name was changed to Emerson as of March 9, 1909.[3][23] The name came from author Ralph Waldo Emerson.[24][25] The borough calls itself “The Family Town”.[26]

Washington was incorporated as a borough by an act of the New Jersey Legislature on February 20, 1868, from portions of Washington Township.[21] The borough was named for George Washington, one of more than ten communities in the state of New Jersey that were named for the first president.[22][23] The Borough of Washington is surrounded by Washington Township, which is one of five municipalities in the state of New Jersey with the name “Washington Township”.[24]

Rumson was formed by an act of the New Jersey Legislature on March 15, 1907, from portions of Shrewsbury Township, based on results of a referendum held on June 18, 1907.[20][21]

Palmyra was originally incorporated as a township by an act of the New Jersey Legislature on April 19, 1894, from portions of Cinnaminson Township and Riverton. On February 20, 1923, Palmyra was reincorporated as a borough.[21]

Berlin was incorporated as a borough on March 29, 1927, from portions of Berlin Township, based on the results of a referendum held on April 26, 1927.[20]

Haddon Heights was incorporated as a borough by an act of the New Jersey Legislature on March 2, 1904, from portions of the now-defunct Centre Township and parts of Haddon Township.[18] Haddon Heights is a dry town where alcohol cannot be sold.[19][20] The borough was named for Elizabeth Haddon, an early settler of the area.[21]

Dunellen was formed as a borough by an act of the New Jersey Legislature on October 28, 1887, when it broke away from Piscataway Township, based on the results of a referendum held on March 23, 1886. Dunellen’s incorporation was confirmed on April 15, 1914.[18] The borough was named for the Dunellen station of the Central Railroad of New Jersey.[19]

Upper Deerfield Township was incorporated as a township by an act of the New Jersey Legislature on February 23, 1922, from portions of Deerfield Township, based on the results of a referendum held on April 3, 1922.[19][20] The township was named for Deerfield Township, which in turn was named for Deerfield, Massachusetts.[21]