Milltown was incorporated as a borough by an act of the New Jersey Legislature on January 29, 1889, from portions of North Brunswick, based on the results of a referendum held three days earlier. The borough was reincorporated by resolution of the borough council on May 2, 1896. A portion of East Brunswick Township was annexed in 1902.[20] Originally known as Bergen’s Mill, named for Jacob I. Bergen who owned the grist mill,[21] the name is believed to have become “Milltown” from residents “going to the mill in town”.[22]

The area became known as “Barrington” in the 1880s, when William Simpson, one of the partners that developed the area, chose the name from his home in Great Barrington, Massachusetts.[20]

Keyport was originally formed as a Town on March 17, 1870, from portions of Raritan Township (now Hazlet). On April 2, 1908, the Borough of Keyport was formed, replacing Keyport Town.[23]

Wharton was originally incorporated as the borough Port Oram by an act of the New Jersey Legislature on June 26, 1895, created from portions of Randolph Township and Rockaway Township, subject to the results of a referendum passed on the previous day; the name was changed to Wharton on April 16, 1902, based on a referendum held that day and subject to legislation passed on March 27, 1902.[16][17][18] The borough was named for Joseph Wharton of the Wharton Steel Company.[19][20]

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]