Power Washing in South Brunswick Terrace, NJ

South Brunswick Township was incorporated by an act of the New Jersey Legislature on February 21, 1798. In the 18th and 19th centuries, the community was primarily agricultural. The Straight Turnpike, now Route 1, was constructed in 1804. The township got its name from New Brunswick, which in turn was named after the city of Braunschweig (called Brunswick in the Low German language), in state of Lower Saxony, in Germany. Braunschweig was an influential and powerful city in the Hanseatic League, later in the Holy Roman Empire, and was an administrative seat for the Duchy (and later Principality) of Hanover. Shortly after the first settlement of New Brunswick in colonial New Jersey, George, Duke of Brunswick-Lüneburg, and Elector of Hanover, of the House of Hanover (also known as the House of Brunswick), became King George I of Great Britain (1660-1727). Alternatively, the city derived its name from King George II of Great Britain, the Duke of Brunswick-Lüneburg.

In 1872, the Legislature first reduced the size of South Brunswick with the creation of the separate Cranbury from the southern portion of South Brunswick. In 1885, it redefined and enlarged the boundaries of Cranbury, and Plainsboro was formed in 1919. The present boundaries of South Brunswick date back to this last change.

During the 20th century, South Brunswick saw extensive transformation with the impact of changes in transportation technology. The New Brunswick and Trenton Fast Line began operation in 1900, a trolley line running parallel to the Old Straight Turnpike of 1804 (Route 1), intersecting George’s Road just north of the Five Corners intersection in Dayton. This trolley provided daily passenger and freight service, stopping at a local crossroads. The New Jersey Turnpike opened in 1951, again roughly parallel to Route 1, on the eastern edge of the Township. One effect of the Turnpike opening up Interchange 8A (just outside the township) was the transformation of the agricultural area on the southeast corner of South Brunswick to that of a burgeoning industrial development. Significant portions of land between Route 130 and the turnpike consist largely of warehouses.