Oil Company in East Northport, NY.

Soon after the establishment of a village in the Huntington area, English settlers sought to further expand their territory. On July 30, 1656, land was purchased from Chief Asharoken, head of the Matinecocks Native American tribe, part of which consisted of the land that is today known as East Northport.

Two distinct communities formed in the area now known as East Northport. The more populous settlement known as Larkfield was located on the northern side, near Vernon Valley (now part of Northport). Larkfield originally developed near the location of Genola Cemetery, just north of the modern-day junction of Larkfield Road, Vernon Valley Road, and Laurel Road. A second community located on the southern side was known as Clay Pitts, named for its vast deposits of red clay. This clay which had been used by Native Americans to form pottery was used by the Europeans to form bricks for construction. The land between Larkfield and Clay Pitts was well suited for agriculture, and the region prospered in the late 18th century as a thriving farming community by supplying produce to markets in New York City and Brooklyn.

In 1868 the Long Island Rail Road opened a station within the village of Northport. However, just a few years later the LIRR decided to move the Northport station to a new location in Larkfield to facilitate further railway extension to Port Jefferson. The new railway station located at Larkfield Road and Bellerose Avenue opened on January 13, 1873. Although the station retained the name of Northport, train conductors would refer to it as “East of Northport”, because the station was located east of the railway junction which used to direct trains north to the old station located in the village of Northport. Despite the fact that East Northport is primarily south of Northport, the area became known thereafter as East Northport. The Larkfield Post Office formally changed its name to East Northport in 1910. The East Northport, New York post office building was renamed the Jerome Anthony Ambro, Jr. Post Office Building in 1998.