The first Fort Adams was designed by Major Louis de Tousard of the Army Corps of Engineers as part of the first system of US fortifications.
After some additions in 1809, this fort mounted 17 cannon and was garrisoned during the War of 1812 by Wood's State Corps of Rhode Island militiamen.
The Secretary of War's report for December 1811 describes the fort as "an irregular star fort of masonry, with an irregular indented work of masonry adjoining it, mounting seventeen heavy guns. ...
The barracks are of wood and bricks, for one company".

After the War of 1812, there was a thorough review of the nation's fortification needs and it was decided to replace the older Fort Adams with a newer and much larger fort.
This was part of what became known as the third system of US fortifications.
The new fort was designed by Brigadier General Simon Bernard, a Frenchman who had served as a military engineer under Napoleon.
Bernard designed the new Fort Adams in the classic style and it became the most complex fortification in the Western Hemisphere.
It included a tenaille and crownwork, a complex outer work on the southern (landward) side, designed to break up and channel an assault force.
The fort also had a detached redoubt 650 yards south of the main fort.
In the US, it is rivaled in size only by Fort Monroe in Hampton, Virginia and Fort Jefferson on the Dry Tortugas in Florida.

Construction of the new fort began in 1824 under 1st Lt.
Andrew Talcott and continued at irregular intervals until 1857.
From 1825 to 1838 construction was overseen by Lieutenant Colonel Joseph Gilbert Totten, the foremost American military engineer of his day.
In 1838 Totten became Chief of Engineers and served until his death in 1864.

The new Fort Adams was first garrisoned in August 1841, functioning as an active Army post until 1950.
 During this time the fort was active in five major wars (the Mexican–American War, American Civil War, Spanish–American War, World War I and World War II) but never fired a shot in anger.

At the start of the Mexican–American War the post was commanded by Benjamin Kendrick Pierce, the brother of President Franklin Pierce.
The fort's redoubt, about 1/4 mile south of the main fort, was built during this war.

From 1848 to 1853, Fort Adams was commanded by Colonel William Gates, a long serving veteran of both the War of 1812 and the Mexican War.
The fort's garrison was ordered to California and many of the soldiers lost their lives when the steamer SS San Francisco was wrecked, but not sunk, in a North Atlantic storm on December 24, 1853.

In a report of 1854 Fort Adams was armed with 100 32-pounder seacoast guns, 57 24-pounder seacoast guns, and 43 24-pounder flank howitzers.
All of these weapons were smoothbore cannon.
The flank howitzers were short-barreled guns deployed in casemates in the tenaille and redoubt to protect the fort against a landward assault.

From 1859 to 1863 the fort was in the care of Ordnance Sergeant Mark Wentworth Smith, a Mexican–American War veteran who was wounded at the Battle of Chapultepec.
Sergeant Smith died in 1879 at the age of 76, the oldest active duty enlisted soldier in the history of the Army.
The first Fort Adams was designed by Major Louis de Tousard of the Army Corps of Engineers as part of the first system of US fortifications. After some additions in 1809, this fort mounted 17 cannon and was garrisoned during the War of 1812 by Wood's State Corps of Rhode Island militiamen. The Secretary of War's report for December 1811 describes the fort as "an irregular star fort of masonry, with an irregular indented work of masonry adjoining it, mounting seventeen heavy guns. ... The barracks are of wood and bricks, for one company".
After the War of 1812, there was a thorough review of the nation's fortification needs and it was decided to replace the older Fort Adams with a newer and much larger fort. This was part of what became known as the third system of US fortifications. The new fort was designed by Brigadier General Simon Bernard, a Frenchman who had served as a military engineer under Napoleon. Bernard designed the new Fort Adams in the classic style and it became the most complex fortification in the Western Hemisphere. It included a tenaille and crownwork, a complex outer work on the southern (landward) side, designed to break up and channel an assault force. The fort also had a detached redoubt 650 yards south of the main fort. In the US, it is rivaled in size only by Fort Monroe in Hampton, Virginia and Fort Jefferson on the Dry Tortugas in Florida.
Construction of the new fort began in 1824 under 1st Lt. Andrew Talcott and continued at irregular intervals until 1857. From 1825 to 1838 construction was overseen by Lieutenant Colonel Joseph Gilbert Totten, the foremost American military engineer of his day. In 1838 Totten became Chief of Engineers and served until his death in 1864.
The new Fort Adams was first garrisoned in August 1841, functioning as an active Army post until 1950.  During this time the fort was active in five major wars (the Mexican–American War, American Civil War, Spanish–American War, World War I and World War II) but never fired a shot in anger.
At the start of the Mexican–American War the post was commanded by Benjamin Kendrick Pierce, the brother of President Franklin Pierce. The fort's redoubt, about 1/4 mile south of the main fort, was built during this war.
From 1848 to 1853, Fort Adams was commanded by Colonel William Gates, a long serving veteran of both the War of 1812 and the Mexican War. The fort's garrison was ordered to California and many of the soldiers lost their lives when the steamer SS San Francisco was wrecked, but not sunk, in a North Atlantic storm on December 24, 1853.
In a report of 1854 Fort Adams was armed with 100 32-pounder seacoast guns, 57 24-pounder seacoast guns, and 43 24-pounder flank howitzers. All of these weapons were smoothbore cannon. The flank howitzers were short-barreled guns deployed in casemates in the tenaille and redoubt to protect the fort against a landward assault.
From 1859 to 1863 the fort was in the care of Ordnance Sergeant Mark Wentworth Smith, a Mexican–American War veteran who was wounded at the Battle of Chapultepec. Sergeant Smith died in 1879 at the age of 76, the oldest active duty enlisted soldier in the history of the Army.
Fort Adams