Fort Jay became obsolete shortly after being built. A second fort was constructed nearby. This is Castle Williams. It is named after its builder, Benjamin Franklin's nephew,Lt. Col. Jonathan Williams. Williamsburg, Brooklyn was also named after him.
Castle Williams was state-of-the-art when built. It was also one of the first forts designed by an American. Built to protect the city from the British in 1812. It, along with Castle Clinton on Manhattan, was so successful the British decided to burn a different city further south.