The fort was named for Union General Horatio G. Wright, a former Chief of Engineers who was born in Clinton, Connecticut.

[2] Fort H. G. Wright was built as part of the large-scale Endicott Program, which recommended a comprehensive replacement of existing coast defenses.

Battery Dynamite, on Race Point at the southwest end of the island, had a 15-inch pneumatic gun firing a dynamite-loaded projectile.

This type of weapon was determined to be inferior to conventional guns and was withdrawn from service in 1904.

[2] Following the American entry into World War I in April 1917, changes were made at the stateside forts with a view to putting some coast artillery weapons into the fight on the Western Front.

In 1917 the four 6-inch (152 mm) M1903 guns of Batteries Hamilton and Marcy were removed from the fort, mounted on field carriages, and sent to France.

[2] However, a history of the Coast Artillery in World War I states that none of the regiments in France equipped with 6-inch guns completed training in time to see action before the Armistice.

[2] None of the removed guns at Fort H. G. Wright were replaced, and in 1920 the carriages were ordered scrapped.

[6] Harbor defense in the Long Island Sound area was based on building two 16-inch (406 mm) gun batteries at Camp Hero in Montauk.

[6] Fort H. G. Wright did receive some new batteries during the war, but the heavier portions of them were never mounted, as the threat from German surface ships was negligible by 1943.

[5] A naval training school for "indicator loops" (for magnetic detection of submarines) operated on the island as well.