Prior to its closing in 1994, the fort was claimed to be the longest continuously garrisoned military installation in the United States.

It comprises several fortifications, including Fort Tompkins and Battery Weed and was given its present name in 1865 to honor Brigadier General James Wadsworth, who had been killed in the Battle of the Wilderness during the Civil War.

By 1835 Forts Richmond (now Battery Weed) and Tompkins had deteriorated to the point that they were declared unfit for use, and the next year the federal government began a decade-long process of purchasing them.

[6] The four-tier arrangement was only duplicated in the United States by Castle Williams on Governors Island and Fort Point in San Francisco, California.

The new defenses were mainly armed with Rodman guns, large smoothbores of 15-inch and 10-inch caliber along with 8-inch converted rifles.

[2][8] Battery Hudson included an emplacement for the United States' first type of disappearing gun, a 15-inch Rodman on King's depression carriage, which was not widely adopted.

The 1885 Board of Fortifications, chaired by Secretary of War William C. Endicott and also called the Endicott Board, recommended sweeping improvements to US coast defenses, with a new generation of modern breech-loading rifled guns and numerous new gun batteries.

Most of the Board's recommendations were adopted as the Endicott program, and that included major changes and improvements for Fort Wadsworth.

[1] From 1896 to 1905 the following batteries were completed at Fort Wadsworth:[3][9] Facilities for planting and controlling an underwater minefield were also built.

At that time most of the Endicott batteries were still years from completion, and it was feared the Spanish fleet would bombard East Coast ports.

[3] In 1910, the fort fired a 21-gun salute to former President Theodore Roosevelt as his ship passed through the Narrows on his return from a nearly year-long trip to Africa and Europe.

[11] In 1913, ground was broken by President William Howard Taft for a proposed National American Indian Memorial that was to be built on the site of Fort Tompkins.

The monument was to include a 165-foot-tall (50 m) statue of an American Indian on the bluff overlooking the Narrows, but difficulties in fundraising and the advent of World War I precluded fruition of the plan.

[3] Most coastal forts in CONUS had their garrison reduced to provide crews for heavy and railway artillery units destined for the Western Front.

By 1924, Fort Wadsworth had become an infantry post, with the coast artillery batteries in caretaker status, with only a few soldiers garrisoned for maintenance.

[9] Although Fort Wadsworth was an important mobilization center, it received little new armament in World War II.

[15]: 3  With the 1996 closure of the United States Coast Guard Atlantic Area headquarters and base at Governors Island, their New York-based operations moved to Fort Wadsworth, as tenants in some of the buildings and housing previously occupied by the Navy.

As of 2007, some Fort Wadsworth buildings are occupied by the United States Coast Guard's Sector New York[16] and Maritime Safety and Security Team 91106.

Historic structures include Battery Weed, directly on the harbor, and Fort Tompkins on the bluff above.

There are several smaller early 20th Century coastal artillery batteries and an overlook with panoramic views of the Upper Bay, Brooklyn and Manhattan.

The National Park Service currently maintains a visitors' center on site and offers ranger-led tours of the facilities.

The Five Boro Bike Tour is an annual recreational cycling event in New York City that starts at Battery Park in Lower Manhattan and ends with a festival in Fort Wadsworth.