The Military Fort Standing Strong Since 1632

Forts are an integral part of any nation's architecture, fortified buildings that have historically protected cities and towns from outside offensives and act as a safeguard for those who reside within. The United States has hundreds of forts across the nation, ranging from military posts to fortresses found along coastal and inland regions. Forts have always been a key component throughout history and even before our Forefathers founded America, they were a key component.

According to the National Park Service, one of the first things settlers did when they arrived in the New World was to build forts. This was done to establish ownership and provide security against other nations trying to assert dominance and take the land.Some forts survived the conflicts, but others, like those in Jamestown, Virginia, are remains of what once was.

To determine historic military forts standing strong today, 24/7 Tempo consulted websites including Legends of America, Military History Fandom, and the National Park Service. In most cases, the original forts have not survived intact, however, in addition to some surviving structures, the sites contain ruins, reconstructed facilities, or historically accurate replicas of the original fort grounds. This list provides only a few examples. Note that many of these forts remained in use after American independence. (These are the longest wars of all time.)

These forts played significant roles, besides defending seaports from foreign navies and deterring attacks on the frontier. They were also the sites of important historical events, including the signing of treaties, visits from famous figures, and – in the case of Fort Johnson – the first time the South Carolina state flag was raised.The advances in modern warfare have all but rendered forts obsolete. Many fort sites are now museums, while others may be temporarily closed awaiting repairs.

Here are historic military forts standing strong today.

• Location: New Castle, NH
• Established: 1632

Originally known as The Castle and then Fort William and Mary, Fort Constitution was built by the British to guard access to the harbor at Portsmouth. The Patriots captured this fort during the Revolutionary War. In 1808 the fort was rebuilt and renamed Fort Constitution. It expanded through 1899, ultimately operating through the 1950s.

Visitors can still check out ruins from the 1808 structure. Now part of a New Hampshire state park, the site is also home to the Portsmouth Harbor Light, a lighthouse completed in 1878.

• Location: Marblehead, MA
• Established: 1634

One of the oldest English coastal fortifications, Fort Sewall was last used during the Spanish-American War in 1898. In 1922, the federal government turned the fort over to the town of Marblehead, and it's now open as a public park. Thanks to a 1.5 million dollar rehabilitation effort, the Fort Sewall Oversight Committee gave the structures a recent facelift, re-creating a gun platform and restoring the masonry work.

• Location: Winter Island, MA
• Established: 1643

Fort Pickering served as a strategic coastal defense and military barracks for Salem Harbor over several periods, from the Anglo-Dutch Wars through World War II. Today, you can visit the Civil War-era remains of the fort as part of the Winter Island Maritime Park.

• Location: New Haven, CT
• Established: 1659

Several forts have stood on this site, beginning with an unnamed British structure. In 1776, colonists built a new fortification in New Haven, dubbed Black Rock Fort. Before the War of 1812, it was reconstructed and named after American patriot Nathan Hale.

The fort became a historic site in 1921, and after years of neglect, it was brought back to life with the formation of the Fort Nathan Hale Restoration Project.Rededicated in 1976, the fort is now the focal point of a 20-acre city park that draws visitors worldwide.

• Location: St. Augustine, FL
• Established: 1672

First erected when Florida was part of the Spanish empire, Castillo de San Marcos is the oldest surviving masonry fort in the country. The fort has changed hands five times under four governments, serving as a designated U.S. Army base beginning in 1821. The Castillo de San Marcos National Monument has become a popular tourist attraction and has cannon firings and weaponry demonstrations for visitors.

• Location: Bristol, ME
• Established: 1692

Fort William Henry was once New England's largest fort but the original structure was destroyed by New France in the Siege of Pemaquid in 1696. The state of Maine rebuilt it in 1908, using many of the original stones. Today, Fort William Henry is part of the Colonial Pemaquid State Historic Site, which includes the archaeological excavations of 17th- and 18th-century villages, period buildings, and a museum.

• Location: Kittery Point, ME
• Established: 1715

Throughout the 19th century, Fort McClary helped protect the approaches to the harbor of Portsmouth, New Hampshire, and the Portsmouth Naval Shipyard in Kittery. The surviving structures at what is now a state historic site include a blockhouse from 1844 and the Magazine Building, which was built around 1808 and is considered the oldest structure on the site.

The blockhouse houses a museum, exploring the fort's role in history, and is open daily from Memorial Day to Columbus Day.

• Location: Wetumpka, AL
• Established: 1717

The government of French Louisiana erected Fort Toulouse as a counter to the increasing influence of the British colonies of Georgia and Carolina. At the end of the French and Indian War in 1763, the fort was abandoned and was left in disrepair. Fort Jackson was built on top of it in 1814 during the Creek War.

A replica of Fort Toulouse was built during the American Bicentennial in the mid-1970s but unfortunately was inaccurately positioned upon the outline of the much larger Fort Jackson. The Alabama Historical Commission rebuilt the replica in the 1980s. Visitors can see the recreated 1751 Fort Toulouse, Creek Indian houses, and the partially restored Fort Jackson at Fort Toulouse-Fort Jackson State Historic Site.

• Location: San Antonio, TX
• Established: 1718

One of the most popular historic spots in the country is the site of the Battle of the Alamo, which occurred in 1836, where folk heroes James Bowie and Davy Crockett died. Today, this tourist destination is a museum in the Alamo Plaza Historic District and a part of the San Antonio Missions World Heritage Site.

The site is open daily, except for Christmas Day, and guided tours for families, audio tours, history talks, and events are ongoing.

• Location: Prairie du Rocher, IL
• Established: 1720

This French fortification has been rebuilt multiple times, mainly due to repeated flooding from the Mississippi River. It was first used as an administration center for a province of New France and was later operated by the British until it was abandoned and left to deteriorate in 1772.

The present-day Fort de Chartres State Historic Site contains an imaginative reconstruction of parts of the third version of Fort de Chartres. The stone masonry powder magazine is the only structure from the 1772 incarnation that survived, and it's considered the oldest building in Illinois.

• Location: Darien, GA
• Established: 1721

The southernmost outpost of the British Empire in North America, Fort King George was guarded for the first seven years by His Majesty's Independent Company. However, disease, threats of Spanish and Indian attacks, and the harsh coastal environment resulted in the deaths of 140 officers. The fort was abandoned until 1736 when General James Oglethorpe brought Scottish Highlanders to the site.

The new settlement, called Darien, eventually became an exporter of lumber. Through old records and drawings, the fort was reconstructed with a blockhouse, officers' quarters, barracks, a guardhouse, and a moat.

• Location: Porter, NY
• Established: 1726

New France originally built Fort Niagara to control access between the Niagara River and Lake Ontario, protecting its interests in North America. The British took over the fort during the French and Indian War and stayed until 1796, after the signing of the Jay Treaty.

The U.S. Coast Guard continues to have a presence at the fort, though it has been deactivated since 1963.The 18th-century buildings are open to the public.

• Location: St. Augustine, FL
• Established: 1742

The Spanish constructed Fort Matanzas to ward off British invasions of St. Augustine. Spain lost control of Florida with the 1763 Treaty of Paris and stopped maintaining the fort. When the United States took control of Florida in 1821, it deemed Fort Matanzas uninhabitable for its troops.

However, beginning in 1916, the U.S. Department of War began a major restoration. Today, the Fort Matanzas National Monument offers free ferry rides to see the fort.

• Location: Charlestown, NH
• Established: 1744

The Fort at Number 4 was a stockade fortification protecting the northwesternmost village in the British colonies – Plantation Number 4. The fortification was a rectangle of six houses connected with lean-tos, created when the townsfolk voted to move several of their homes to build a barricade. The original fort deteriorated after the Revolutionary War, but a recreation was constructed in 1960, and it is now an open-air museum.

This colonial Spanish fort changed hands several times, depending on which nation governed the area – Great Britain, Spain, the United States, or the Confederacy – during the Civil War. In 1859, the United States Marines built a hospital from the old fort's limestone and flint rock. Today, visitors to the San Marcos de Apalache Historic State Park can check out a museum with artifacts from the original fort and a visitor center, located on the foundation of the old hospital.

• Location: Winslow, ME
• Established: 1754

The solitary blockhouse at Fort Halifax is the oldest of its kind in the United States today. The wooden palisaded fort was originally constructed by the British during the French and Indian War, hoping to keep Canadians and their Native American allies from attacking English settlements via the Kennebec River Valley.

Fort Halifax also hosted troops under Colonel Benedict Arnold on their way to Quebec during the American Revolution. Everything aside from the surviving blockhouse was dismantled after that. The west side of Fort Halifax Park is the site of continuous archaeological explorations.

• Location: Ticonderoga, NY
• Established: 1755

This star-shaped fort near the south shores of Lake Champlain in New York State was built by French-Canadians during the Seven Years' War. The British controlled the fort from 1759 until 1775 when it was captured by the Americans in a surprise attack.

Even though the fort returned to British hands in 1777, it was ultimately abandoned. A private family restored the fort was restored in the early 20th century, and today it's a museum and tourist attraction.

• Location: Oswego, NY
• Established: 1755

This British fort has been destroyed and rebuilt several times since it was first erected during the French and Indian War. It also served as a military hospital and housed Jewish refugees during World War II. The restored fort is now open to the public as a state historic site from May through early October.

• Location: Big Pool, MD
• Established: 1756

The colony of Maryland constructed this large stone fort during the French and Indian War, mainly as a refuge for area settlers. The fort later served as a prisoner-of-war camp during the Revolutionary War, with up to 1,000 captured British and German soldiers.

By 1922, when the property was acquired by the state of Maryland, the walls had deteriorated but were standing up to eight feet high in places.A complete reconstruction was possible, thanks to the discovery of the original plans and archaeological investigations.

• Location: Vonore, TN
• Established: 1756

Constructed by the British in what is now Monroe County, Tennessee, Fort Loudoun was meant to encourage Cherokee support for the British at the outset of the French and Indian War. However, the relationship soured after a massacre of several Cherokee chiefs, and the Cherokee attacked the fort in 1760.

The fort was rebuilt during the Great Depression, and the Fort Loudoun State Park offers an interpretative center featuring artifacts excavated before the Fort's reconstruction.

• Location: Metropolis, IL
• Established: 1757

This colonial and early-national-era fort on the Ohio River was abandoned by the French after the French and Indian War and destroyed by the Chickasaw at some point after 1763. The fort rose again in 1794 during the Northwest Indian War.

It hosted the Lewis and Clark Expedition in 1803 and General James Wilkinson and Vice President Aaron Burr in 1805 before it was decommissioned in 1814. A partial reconstruction from the 1970s was torn down in 2002 and replaced with a smaller, more detailed version of the fort, as it would have appeared in 1802.

• Location: Rome, NY
• Established: 1758

This bastion fort is significant as the site of the 1768 Treaty of Fort Stanwix between Britain and Native American tribes and the 1784 Treaty of Fort Stanwix between the tribes and the American government. The fortifications were dismantled after 1828, and a reconstruction was completed in 1978.

The Marinus Willett Collections Management and Education Center serves as a regional tourism center, housing the Fort Stanwix National Monument's nearly 500,000 artifacts, documents, and exhibits.

• Location: Ligonier, PA
• Established: 1758

This was a British fortification from the French and Indian War and operated as a staging area for the Forbes Expedition of 1758. During Pontiac's War of 1763, the fort served as a vital link in the British communication and supply lines. It was attacked and besieged by the Native Americans before the victory at Bushy Run that year and decommissioned in 1766.

The fort's cannons are fired on Fort Ligonier Days and an 18th Century Reenactment is held every year on Memorial Day weekend.

• Location: Statesville, NC
• Established: 1761

This 18th-century fort was used as a frontier defense during and after the French and Indian War, protecting the American settlers from French-allied Native Americans and serving as a major outpost for soldiers, traders, and colonial officials. Though Fort Dobbs largely decayed after it was abandoned in 1761, archaeology and historical research helped determine its exact location and likely appearance.

Reconstruction was completed in 2019 and tourists can now "visit" with soldiers from wars past on the Fort Dobbs State Historic Site, with reenactments and demonstrations during events like the Military Timeline and Winter With the Western Company.

• Location: James Island, SC
• Established: 1765

Continually expanded during the French and Indian War, the Revolutionary War, and the War of 1812, this fort was the site of the first raising of the South Carolina state flag in 1775. A magazine constructed in 1765 was buried during the Civil War by Confederate soldiers and uncovered in 1931 and is one of a few items left from the era.

The South Carolina Department of Natural Resources now operates the site, and the College of Charleston uses a small part as a teaching and research facility.