Fort (first) is built on Castle Island.

(OS-7/29) Construction of the fort is approved after Gov. Thomas Dudley and “divers Ministers and others” visit the site on this day. An earthworks structure containing two platforms and three cannon called “The Castle,” it is the first of eight forts built on the island. Capt. Simpkins of the Ancient and Honorable Artillery Company is the first commander. Three cannon are installed in 1635. The garrison and ordnance are subsequently abandoned, until an embarrassing incident occurs when a French ship enters the Port of Boston unchallenged in 1643.* The fort is replaced 1644,* 1653,*, 1673,*, 1703,* 1799,* 1803,* and 1851.*