The Conanicut Battery was built by order of the Rhode Island General Assembly in 1776.  The original fort was probably a simple, crescent-shaped earthwork designed to house and protect six to eight heavy cannon and their men. During their four-year occupation of Newport, the British rebuilt the earthworks in the shape seen today. Surrounded by a ditch and with bastions extended at each end, it was designed both to repel land attacks and to house heavy cannons in defense of West Passage.

After the Revolution, the grounds reverted to private use as farmland until 1916, when the US Government purchased 16 acres as part of a new fortification of Narragansett Bay. The six underground observation posts built remained in use by the military through World War II.

In 1963 the property was deeded to the town. In 1972 Conanicut Battery was placed on the National Register of Historic Places.