The Harbor Defenses of Long Island Sound was a United States Army Coast Artillery Corps harbor defense command. It coordinated the coast defenses of Long Island Sound and Connecticut from 1895 to 1950, beginning with the Endicott program. These included both coast artillery forts (all but two on islands in the sound) and underwater minefields. The area defended included the approach via the Sound to New York City, the port cities and manufacturing centers of New London, New Haven, and Bridgeport, and eventually included the submarine base and shipyard in Groton. The command originated circa 1900 as an Artillery District, was renamed Coast Defenses of Long Island Sound in 1913, and again renamed Harbor Defenses of Long Island Sound in 1925.Stanton, pp. 455-481Coast Artillery Organization: A Brief Overview at the Coast Defense Study Group websiteRinaldi, pp. 165-166Berhow, pp. 430-434
History Early Long Island Sound forts
Colonial period
Connecticut appears to have had few coastal fortifications in the colonial era. Unnamed forts are referred to in New Haven at the site of the later Black Rock Fort (dating from 1657)Black Rock Fort (New Haven) at American Forts Network and in New London at the later Fort Trumbull.Roberts, pp. 120, 124-125 The British Fort Saybrook was established at Old Saybrook in 1635, which burned in 1647, but was rebuilt the next year on a new site. It was successful in resisting a Dutch raid in 1675.Fort Saybrook at American Forts Network
Revolutionary War
Two relatively large and at least four small coastal forts were built in Connecticut during the American Revolutionary War. The larger ones were Fort Trumbull in New London and Fort Griswold in Groton, across the Thames River from Fort Trumbull. Smaller forts were also built in New Haven (Black Rock Fort), in a part of Fairfield called Black Rock that is now in Bridgeport (confusingly also called Fort Black Rock), and at Long Point in Stonington Borough.Roberts, pp. 117, 120, 121Black Rock Fort (Black Rock) at American Forts NetworkLong Point Fort at American Forts Network These were all built 1775–1778. Following a British raid on Stamford in July 1781, Fort Stamford was hastily built there.Roberts, pp. 123-124Fort Stamford at American Forts Network One source states that Fort Saybrook was also rebuilt in the Revolution.
British and Loyalist (a.k.a. Tory) forces conducted several raids in Connecticut during the war. One was Tryon's raid under William Tryon in July 1779, which attacked New Haven, Fairfield, and Norwalk, with success in burning the latter two towns. The raid also captured New Haven and Black Rock Fort, but a subordinate of Tryon's limited his activities to destruction of military-related stores and ignored orders to burn the city. In Fairfield, Fort Black Rock was besieged but not taken, but was unable to prevent the British from entering the town by another route. The most famous British raid in Connecticut was at New London and Groton under the traitor Benedict Arnold on 6 September 1781. His forces readily captured Fort Trumbull (defended by only 23 men and open on the landward side) and overcame a stiff resistance at Fort Griswold in the Battle of Groton Heights. Contemporary patriot newspaper accounts allege that the British and Loyalist forces massacred many of the defenders of Fort Griswold after their surrender, starting with their commander, Colonel William Ledyard, who it was said was run through with his own sword after surrendering it.The Pennsylvania Gazette, 26 September 1781 The garrison of about 150 suffered 85 killed. The British forces went on to burn the city of New London. and
1783-War of 1812
Fort Trumbull was repaired in 1795 and 1799 under the first system of US fortifications, and was repaired in 1808 and rebuilt in 1813 with 18 guns under the second system, during the War of 1812.Forts Trumbull and Griswold at American Forts Network Fort Griswold received little attention except some repairs in 1794, though it was garrisoned during at least part of the war. The British were able to blockade New London for the duration of the war, keeping three warships under Stephen Decatur bottled up in the Thames River. Decatur had an earthwork fort (named for himself) built on Allyn's Mountain in Gales Ferry, just north of Groton.Fort Decatur at American Forts Network Black Rock Fort in New Haven was rebuilt as the six-gun Fort Hale in 1809–1812.Roberts, p. 120 Various other forts were rebuilt in the War of 1812, some with new names.Connecticut forts at American Forts Network The most famous action in Connecticut of the War of 1812 was the bombardment of Stonington Borough on 9–12 August 1814. A force of four British warships under Sir Thomas Hardy demanded the town's surrender. The town refused, despite having only two 18-pounder cannon with which to defend itself. Three days of bombardment resulted in one elderly woman killed and a few of the defenders wounded, against reportedly 21 British sailors killed and 50 wounded.Steenburg, Nancy, "Attack on Stonington", Connecticut Explored, Summer 2012 Stonington's pair of 18-pounders are preserved in the borough to this day.
1816-1890
Although heavily fortified locations were not attacked in the War of 1812, the British managed to bypass or suppress the weak defenses at the mouth of Chesapeake Bay and burn Washington, DC. As a result, Congress approved a large-scale program of improved masonry forts, later called the third system of US fortifications, to replace the relatively small forts of the first and second systems. Connecticut received a complete rebuild of Fort Trumbull and a rebuilt water battery at Fort Griswold under this program.
The new (and current) Fort Trumbull was built from 1839 to 1850. It was designed by Joseph Totten and built under the supervision of George W. Cullum, both officers of the Army Corps of Engineers. Totten was the leading American fort designer of his day, and Cullum would later become superintendent of the US Military Academy at West Point. Fort Trumbull was built with five sides, three of them facing the water. The main fort could use up to 42 guns on the seacoast fronts, plus flank howitzers in bastions for close-in defense. Two external seacoast batteries added another 10 guns. The two landward fronts had numerous loopholes for muskets, along with cannon on the fort's roof.Weaver, pp. 132–135
The Groton Monument was built near Fort Griswold in 1825–1830 to commemorate the Revolutionary War battle's dead. Fort Griswold's water battery was rebuilt in the 1840s for 20 guns. During the Civil War it was upgraded to accommodate 10-inch Rodman guns.History of Fort Griswold at Friends of Fort Griswold website
Forts in Connecticut served as mobilization centers in the Civil War. Fort Trumbull became the headquarters of the 14th US Infantry regiment during the war. Fort Nathan Hale in New Haven was built in 1863 near the old Black Rock Fort as an earthwork mounting 18 guns, with bomb-proof shelters and magazines. In an unusual move, this fort was partially demolished after the war.Fort Nathan Hale at American Forts NetworkFort Nathan Hale at FortWiki.com
The Civil War had shown that masonry forts were vulnerable to modern rifled cannon, particularly in the siege of Fort Pulaski near Savannah, Georgia, in 1862. Also, the 15-inch (381 mm) smoothbore Rodman gun was introduced during the war. New earth-protected batteries were constructed in the 1870s at a number of locations to provide more survivable forts armed with the new weapons. However, Connecticut does not seem to have received any improved fortifications, and the program was terminated in 1878.
Endicott period
The Board of Fortifications was convened in 1885 under Secretary of War William Crowninshield Endicott to develop recommendations for a full replacement of existing coast defenses. Most of its recommendations were adopted, and construction began in 1897 on new forts to defend Long Island Sound.Map of HD Long Island Sound at FortWiki.com Initially, three large and one small forts were built. The large forts were Fort H. G. Wright on Fishers Island, Fort Michie on Great Gull Island, and Fort Terry on Plum Island. All three of these forts are in New York state in the town of Southold in Suffolk County, and the islands they are on define the border between Block Island Sound and Long Island Sound. The small fort was Fort Mansfield, on Napatree Point in Westerly, Rhode Island.Berhow, pp. 207-208 Two underwater minefields controlled from Fort H. G. Wright and Fort Terry also guarded the Sound.Fort H.G. Wright at FortWiki.comFort Terry at FortWiki.com This harbor defense command was one of those in which new fort locations moved seaward (compared to Forts Trumbull and Griswold) as gun ranges increased. Fort Trumbull was the initial headquarters for Long Island Sound's defenses, but in 1910 this shifted to Fort H. G. Wright and Fort Trumbull became the Revenue Cutter Academy.
Heavy weapons included a rare 15-inch (381 mm) dynamite gun at Fort H. G. Wright, along with eight 12-inch (305 mm) mortars and one pair each of 12-inch (305 mm) disappearing guns and 10-inch (254 mm) disappearing guns. Fort Michie had one pair each of 12-inch and 10-inch guns. Fort Terry had eight 12-inch mortars and a pair of 10-inch disappearing guns, along with a pair of 5-inch (127 mm) guns. All of these forts also had between four and seven 6-inch (152 mm) guns and several 3-inch (76 mm) guns to defend the minefields against minesweepers. Fort Mansfield was one of the smallest Endicott forts, with two 8-inch (203 mm) disappearing guns and four 5-inch (127 mm) guns. The initial forts were substantially complete by 1906.
Generally, the heavy batteries were built first, followed by the 3-inch and then the 6-inch batteries. However, the Spanish–American War broke out in early 1898. Most of the Endicott batteries were still years from completion, and it was feared the Spanish fleet would bombard the US east coast. A number of batteries of medium-caliber rapid-fire guns were hastily built, along with batteries of Civil War-era smoothbore Rodman guns.Congressional serial set, 1900, Report of the Commission on the Conduct of the War with Spain, Vol. 7, pp. 3778–3780, Washington: Government Printing Office Fort Terry received a single 4.72-inch (120 mm)/45 caliber Armstrong gun, purchased from the United Kingdom. Unusually, in Long Island Sound a new fort was built in response to the situation. This was Fort Tyler on Gardiners Point Island, south of Plum Island. This fort initially had emplacements for two modern 8-inch M1888 guns (203 mm) on modified 1870s Rodman carriages. The fort was later rebuilt to accommodate two 8-inch disappearing guns and two 5-inch guns. However, records do not indicate that the fort was ever armed or garrisoned.Fort Tyler at FortWiki.com Emergency batteries of 10-inch smoothbore Rodman guns included one gun at Fort Long Point in Stonington, six guns at Fort Nathan Hale in New Haven, and four guns at or near the old Black Rock Fort in Bridgeport. The Rodman gun batteries were disarmed shortly after the war in 1899–1900, and Fort Terry's 4.7-inch gun was transferred to the Sandy Hook Proving Ground in 1903. In 1904 the dynamite gun concept was abandoned and Fort H. G. Wright's gun was removed.
Fort Mansfield was intended to guard the strait between Westerly, Rhode Island and Fishers Island. However, an exercise in 1907 showed that the nearby beach could be invaded in a sector the guns could not cover, thus the fort was vulnerable to capture. The fort was placed in caretaker status in 1909 and disarmed to provide guns for World War I in 1917. It was abandoned and sold in 1928.Fort Mansfield at FortWiki.com