First settled along a tributary of the Raritan River in 1720, South River was known as Willettstown and later as Washington. Part of East Brunswick until 1898, it emerged as an independent borough in Middlesex County with the passage of the state law to incorporate it. Although comprising fewer than three square miles, South River once served as a shipping and transportation link between New York and Philadelphia and has been home to industry since the first brickyard was established in the mid-1800s. Sand and clay mining, brick and tile manufacturing, shipbuilding, and textile and clothing manufacture have played significant roles in the development of the