Fort Carroll is a

artificial island An artificial island or man-made island is an island that has been Construction, constructed by humans rather than formed through natural processes. Other definitions may suggest that artificial islands are lands with the characteristics of hum ...

and abandoned hexagonal

sea fort 300px, Cartagena_de_Indias.html" ;"title="Castillo San Felipe de Barajas in Cartagena de Indias">Castillo San Felipe de Barajas in Cartagena de Indias, Colombia Coastal defence (or defense) and coastal fortification are measures taken to pro ...

in the middle of the

Patapsco River The Patapsco River ( ) mainstem is a river in central Maryland that flows into the Chesapeake Bay. The river's tidal portion forms the harbor for the city of Baltimore. With its South Branch, the Patapsco forms the northern border of Howar ...

, just south of

Baltimore, Maryland Baltimore is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland. With a population of 585,708 at the 2020 United States census, 2020 census and estimated at 568,271 in 2024, it is the List of United States ...

. It is named for

Charles Carroll of Carrollton Charles Carroll (September 19, 1737 – November 14, 1832), known as Charles Carroll of Carrollton or Charles Carroll III, was an American politician, planter, and signatory of the Declaration of Independence. He was the only Catholic signatory ...

(1737–1832), a signer of the

Declaration of Independence A declaration of independence is an assertion by a polity in a defined territory that it is independent and constitutes a state. Such places are usually declared from part or all of the territory of another state or failed state, or are breaka ...

Design and construction

In 1847, the State of Maryland permitted the United States War Department to construct a fort in the shallow water of Soller's Point Flats to protect the city of Baltimore. Fort Carroll was important for the defense of Baltimore—before the fort's construction,

Fort McHenry Fort McHenry is a historical American Coastal defense and fortification, coastal bastion fort, pentagonal bastion fort on Locust Point, Baltimore, Locust Point, now a neighborhood of Baltimore, Maryland. It is best known for its role in the War ...

just outside the city was the only military defensive structure between Baltimore and the

Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The bay is located in the Mid-Atlantic (United States), Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula, including parts of the Ea ...

. The fort was part of the "Permanent System" or

Third System Seacoast defense was a major concern for the United States from its independence through World War II. Before airplanes, many of America's enemies could only reach it from the sea, making coastal forts an economical alternative to standing armies ...

construction program, which aimed to defend America's most important ports. Then Brevet-Colonel

Robert E. Lee Robert Edward Lee (January 19, 1807 – October 12, 1870) was a general officers in the Confederate States Army, Confederate general during the American Civil War, who was appointed the General in Chief of the Armies of the Confederate ...

designed the hexagonal structure and supervised the construction, which the

U.S. Army Corps of Engineers The United States Army Corps of Engineers (USACE) is the military engineering branch of the United States Army. A direct reporting unit (DRU), it has three primary mission areas: Engineer Regiment, military construction, and civil wor ...

commenced in 1848. The fort received its name on October 8, 1850. In 1852, Lee left Baltimore to become Superintendent of the

United States Military Academy The United States Military Academy (USMA), commonly known as West Point, is a United States service academies, United States service academy in West Point, New York that educates cadets for service as Officer_(armed_forces)#United_States, comm ...

at West Point. In 1853, a

lighthouse A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lens (optics), lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways. Ligh ...

, now abandoned, was built on the ramparts to aid navigation into Baltimore Harbor. In 1898, a new lighthouse was built, which is still seen today. It was automated in 1920 and discontinued operations sometime before 1945. The original design foresaw the fort armed with 225 cannons on three levels. However, in April 1861, at the

American Civil War The American Civil War (April 12, 1861May 26, 1865; also known by Names of the American Civil War, other names) was a civil war in the United States between the Union (American Civil War), Union ("the North") and the Confederate States of A ...

outbreak, Fort Carroll's walls were still less than half the planned height of thirty feet. Only five gun platforms were ready, and only two were armed. Still, the Army placed about thirty cannons and occupied the fort throughout the war. In April 1864, torrential rains flooded the fort's magazines, which led the Army to move all the powder and ammunition to Fort McHenry. Fort Caroll Blueprint

Spanish–American War

When the United States entered the

Spanish–American War The Spanish–American War (April 21 – August 13, 1898) was fought between Restoration (Spain), Spain and the United States in 1898. It began with the sinking of the USS Maine (1889), USS ''Maine'' in Havana Harbor in Cuba, and resulted in the ...

in 1898, the Army again defended the fort, although the batteries were completely obsolete by then. The Army, therefore, commenced the construction of modern concrete gun emplacements following the

Board of Fortifications Several boards have been appointed by US presidents or Congress to evaluate the US defensive fortifications, primarily coastal defenses near strategically important harbors on the US shores, its territories, and its protectorates. Endicott Board ...

designs. The Army created three batteries: Battery TowsonThe battery was named in honor of Major General

Nathan Towson Nathaniel Towson (; January 22, 1784 July 20, 1854), also known as Nathan Towson, was a brevet major general in the United States Army. A career soldier, he fought in the War of 1812 as an artillery officer. He served as paymaster of the Army a ...

, U.S. Army. He had served in the War of 1812 and the Mexican War and died July 20, 1854, in Washington, District of Columbia. (two 12"

barbette Barbettes are several types of gun emplacement in terrestrial fortifications or on naval ships. In recent naval usage, a barbette is a protective circular armour support for a heavy gun turret. This evolved from earlier forms of gun protection ...

carriage guns), Battery HeartThe battery was named in honor of Major Jonathan Heart, 2nd U.S. Infantry, who served during the Revolutionary War. He died on November 4, 1791, in action with Indians near

Fort Recovery Fort Recovery was a United States Army fort ordered built by General "Mad" Anthony Wayne during what is now termed the Northwest Indian War. Constructed from late 1793 and completed in March 1794, the fort was built along the Wabash River, wit ...

, Ohio. (two 5-inch M1897 guns on

balanced pillar A disappearing gun, a gun mounted on a ''disappearing carriage'', is an obsolete type of artillery which enabled a gun to hide from direct fire and observation. The overwhelming majority of carriage designs enabled the gun to rotate bac ...

mounts) and Battery AugustinBattery Augustin was named in honor of 2nd Lieutenant Joseph N. Augustin, Jr., 24th U.S. Infantry, who died July 2 1898 of wounds he had received the day before at the

Battle of San Juan Hill The Battle of San Juan Hill (), also known as the Battle for the San Juan Heights, was a major battle of the Spanish–American War fought between an American force under the command of William Rufus Shafter and Joseph Wheeler against a Span ...

. (two 3" balanced pedestal-mount guns). Fort Carroll Panorama

The new batteries were ready by September 1900, well after the war's end. They received their names on March 30, 1903.

World War I and afterwards

After World War I broke out, in 1917, the Army removed the guns from Battery Heart, and in 1918, those from Battery Towson to use elsewhere. By 1920, all guns had been removed from the fort. In March 1921, the Army officially abandoned Fort Carroll and moved whatever military equipment was left to nearby Fort Howard. The

War Department War Department may refer to: * War Department (United Kingdom) * United States Department of War The United States Department of War, also called the War Department (and occasionally War Office in the early years), was the United States Cabinet ...

declared the island excess property in 1923 but took no immediate steps to sell the land. A variety of proposals for the use of the island were advanced, including a prison, as well as a 1923 plan advanced by Baltimore mayor William Broening to place an electric "Welcome to Baltimore" sign on the island, accompanied by a statue of Lord Baltimore. In World War II, the Army used the fort as a firing range. It also served as a checkpoint for vessels. In May 1958, Baltimore attorney Benjamin Eisenberg purchased the island for , intending to put a casino there, but development plans never materialized. The fort is now an

involuntary park Involuntary park is a neologism coined by science fiction author and environmentalist Bruce Sterling to describe previously inhabited areas that for environmental, economic, or political reasons have, in Sterling's words, "lost their value for tec ...

. It is also a site for occasional

urban exploration Urban exploration (often shortened as UE, urbex, and sometimes known as roof and tunnel hacking) is the exploration of manmade structures, usually abandoned ruins or hidden components of the manmade environment. Photography and historical inte ...

s (which constitute

trespass Trespass is an area of tort law broadly divided into three groups: trespass to the person (see below), trespass to chattels, and trespass to land. Trespass to the person historically involved six separate trespasses: threats, assault, battery ...

). In 2013, Preservation Maryland placed Fort Carroll on its list of threatened historic properties. It was listed on the

National Register of Historic Places The National Register of Historic Places (NRHP) is the Federal government of the United States, United States federal government's official United States National Register of Historic Places listings, list of sites, buildings, structures, Hist ...

in 2015. On April 19, 2024, the third temporary alternate channel established after the collapse of the Francis Scott Key Bridge was named after the fort, the beginning of which is to its immediate west. Francis Scott Key Bridge Collapse Alternate Channels

Francis Scott Key Bridge Collapse Alternate Channels

References

Notes

External links