In 1776, an 8-gun earthwork fortification was constructed by patriot forces at the site of Dumpling Rock, which overlooks the strategic East Passage toward Newport.

[2] In 1798, construction was started on a permanent fortification at Dumpling Rock under the supervision of Major Louis Tousard of the Army Corps of Engineers.

Fort Dumpling was in the form of an oval stone tower and was frequently used as an artistic motif and a place for social outings.

The fort was mentioned in the Secretary of War's report on fortifications for December 1811 as being at "the Dumplins" and is described as "a circular tower of stone, with casemates... with a small expense, there can be mounted six or eight heavy guns; and now in an unfinished state".

It was named for Captain Alexander Macomb Wetherill, a Jamestown native who was killed in action during the Battle of San Juan Hill.

Several of these batteries are now overgrown with brush, but they offer what is perhaps the longest linear concrete gun line in the coast defenses of New England.

After the war, Fort Wetherill reverted to "caretaker status," with only a single Coast Artillery sergeant assigned to watch over it and other nearby facilities.

Fort Wetherill was reactivated by the U.S. Army in September 1940 as a major part of the Harbor Defenses of Narragansett Bay, and new barracks were built to house the National Guard's 243rd Coast Artillery Regiment and its 1,200 soldiers.

The property offers walking trails through wooded areas and along the rocky coast, and is a popular destination for scuba diving.

[6] Beginning in the early 20th century, the seven major concrete gun batteries listed below were built and armed at Fort Wetherill.

Batteries Crittenden and Cooke were named for two officers killed in the Battle of the Little Big Horn, also called "Custer's Last Stand".

After the US entered World War I, Battery Zook's three 6-inch guns were removed for service on field carriages on the Western Front in 1917 and were never returned to the fort.

Battery Wheaton was probably also removed from service at this time, but for some reason its guns were exempted from scrapping until the war ended.