Fort Independence Boston, Ma

History of Fort Independence


Fort’s History


In this category, “Fort Independence History,” the core of this web page will be specific to the eight different forts built at this imposing site. Castle Island was originally of glacial origin. It was a mass of sand, gravel, boulders, and clay left when the glaciers retreated between 10,000 and 20,000 years ago. The page will also cover some particular historical events at the Fort. The General Court Of The Colony of Massachusetts constructed the first four Forts in 1634, 1644, 1653, and 1673. The British Military rebuilt it in 1700 and named it Castle William. USA Military completed three reconstructions in 1776, 1809, and 1851. Enjoy reading the details about each modification of the Fort below;

Stragetic Importantance of the Locataion

1775 chart showing shipping channel Boston Harbor
Chart courtsey of

The above 1775 chart shows Castle Island and why this location was strategically important to Boston. The chart shows a  BLACK LINE  where the main shipping channel is in and out of Boston Neck. Thus, it ensured that all ships had to pass closely by the Fort before going to Boston Neck, which placed all ships within the range of the primitive cannons of the time. This location served a dual purpose: to be a good military site and to collect taxes on boats that passed by.

first fort 1634
First Fort Model

The Castle 1634

On July 29, 1634, the General Court of the Colony of Massachusetts met on  Castle Island, and they agreed on “erecting two platforms and one small fortication”. They appropriated 500 pounds for this purpose. The first Fort was constructed under Governor Thomas Dudley and was supervised by Deputy Gov. Roger Ludlow and Captain John Mason of Dorchester. This design produced a “castle in mud walls” with three cannons to defend Boston from attack by sea. The first commander of the Fort was British Captain Nicholas Simpkins.

The garrison consisted of the captain, the gunner, and an undetermined number of men; in 1634, three men enlisted for a year’s service at 10 pounds a year. In 1641, the Court authorized the captain to employ a gunner and his men 150 bushels of Indian corn a year.

The Castle – 1644

After a French Warship visited Boston Harbor, at this point, the French were a traditional enemy. The French arrived seeking aid against fellow Frenchmen in a dispute over trading rights in Nova Scotia. Because no salute to the visiting ship came from the fort, an upgrade of the fort was required. The new fort was reconstructed with pine logs, stone, and earth and had six saker guns and three smaller guns.

To read more about a saker gun, considered a top-of-the-line cannon at the time with a  range of over a mile, could fire  5 to 6-pound balls.

saker gun
Saker gun

The Castle – 1653

Pine logs were substantially used to upgrade “The Castle’s” outermost walls. Commander Richard Davenport died in 1665 after getting struck by lightning while at the fort. Captain Roger Clap was commander from 1665 to 1686.

The Castle – 1673

After an accidental fire destroyed the Fort, it was rebuilt using stone, with 38 guns and 16 culverins in four bastions and six guns in a water battery. The culverins had an effective range of 1800 feet. Demi-culverins were valued by generals for their range, accuracy, and effectiveness.

In 1689, after the overthrow of King James II in England, British Governor Edmund Andros fled to Castle Island. Edmund Andros attempted to streamline the authorities in New England by bringing them more under the king’s control. One of the acts he tried to enforce was the Navigation Act, which prohibited the use of any foreign ship to land in England and also banned the colonies from exporting certain products to any other country except England

The Castle – 1692

Weaponry was upgraded to include 54 cannons, 24 nine pounders, 12 twenty-four pounders, and 18 thirty-two and forty-eight pounders under Governor Sir Williams Phips.

Castle William – 1701

Castle Wiiliam 1701
Castle Wiiliam

Wolfgang William Romer,  the Chief Engineer of British forces in the American colonies, designed a new fort. The new Fort’s armament was increased to over 100 guns. The Fort was now known as “Castle William.” Outside the Fort, Romer added a complex system of outer defenses. An enemy would have to cross three sets of fortifications to enter the Fort—the waterfront, the secondary, and the Fort itself. A lookout tower at the northeast corner of the Fort that surveyed the outer harbor was constructed. Close by and heavily protected were two powder magazines.

During the Stamp Act and Boston Massacre issues, numerous provincial leaders and British troops felt compelled to take refuge inside the Fort. Most British soldiers and officials were stationed on the island for the next six years.

Fort Adams – 1776

In March of 1776, George Washington’s continental army was able to fortify the nearby Dorchester Heights using the cannons that they had taken from Fort Ticonderoga. At the same time, the continental troops provided cover fire in Cambridge on the British forces. Here is a link for more details on the capture and journey of the Fort Ticonderoga cannons to Boston.

The following morning, British Commander General Howe attempted an attack using row boats to Dorchester Heights but had to turn back due to a snowstorm. Now surrounded, Howe decided to remove his 10,000 troops and 1000 loyalist from Boston.

eneral Howes Command Ship
General Howes Command Ship

Commander Howe and American general George Washington had reached a tacit agreement. So long as the British could leave unmolested, they would not destroy downtown Boston. After the British soldiers started some “plundering” in downtown Boston, Howe issued the following proclamation;

“The commander-in-chief finding, notwithstanding former orders that have been given to forbid plundering, houses have been forced open and robbed, he is therefore under a necessity of declaring to the troops that the first soldier who is caught plundering will be hanged on the spot.”

Howe burned down the Fort and destroyed most of its weaponry and ammunition as part of his “gentleman agreed” evacuation with Washington.

General Washington appointed Colonel Richard Gridley, Chief Engineer, to rebuild the star-shaped Fort. Colonel Paul Revere was put in command of the forces stationed at the Fort. The Fort was officially called Fort Adams until 1797, when President John Adams renamed it Fort Independence.

The siege of Boston Harbor started immediately after the Battle of Concord on April 19, 1775. The British troops set up roadblocks on the Boston Neck to prevent rebels from entering the town. This led to a series of battles with a final climax, the events at the Fort and Dorchester Heights. General Howe thought the British would be safe as he had a large navy, while the rebels had a tiny navy. Howe wrote to London during the fall of 1775 requesting to move his troops from Boston to New York but did not get permission to do so until winter had already started settling in New England.


A chart showing Boston Harbor in 1775
A chart showing Boston Harbor in 1775

Fort Independence – 1800

The fort was rebuilt and expanded by military engineer Jean Foncin in 1803. The fort was now described as “a regular pentagon, with bastions of masonry, mounting 42 heavy cannons, with two additional batteries for six guns” and was made of brick.

During the War of 1812, the British Navy was active in Massachusetts Bay but did not enter Boston Harbor because the USS Constitution and a strong fort played a big part in the harbor defense. Colonel John Beck was the Commandant of the fort during the War of 1812.

Importance of Fort Independence

“Looking back over the 350 years and have stood on Castle Island, we may conclude that the seventh fort, the first Fort Independence, 1801-1836, was the most important. There may have been times when the feared or anticipated danger seemed more real – The French and Indian war, the pre-Revolution period, or the Civil War when more personnel were stationed on the island for greater or lesser periods of time. But during the War of 1812 the danger was real. The British controlled Massachusetts Bay and harassed, attacked, and occupied towns seemingly at will.”

“That Boston was NOT attacked was due to Fort Independence and the then prevailing naval thought that sailing vessels with the armament of the day could not successful subdue land fortifications – a theory proven by the unsuccessful British attack on Foncin’s Fort McHenry at Baltimore. The mere presence of Fort Independence was sufficient to defend the town.”

Taken from Book Castle Island and Fort Independence by William J. Reid

Fort Independence – 1833

Work began in 1833 on the final renovation of the fort, with work continuing until 1862. Colonel Sylvanus Thayer first supervised this work and then continued with Charles H. Bigelow and Edward H. Courtenay. To see more details about  Colonel Thayer’s illustrious military career. The fort was made of granite from Rockport, Ma, and had walls 30′ high and 5.5′ thick.

During the Civil War, weaponry included 96 cannons, including some 15″ Rodman guns that could fire a 450-pound shot more than 3 miles. Fourth Battalion Volunteer Militia and two Infantry regiments, the 11th Massachusetts and 13th Massachusetts, used the fort for training and drilling.

Connecting Castle Island to Mainland

In 1890 the city of Boston started filling in the marshes around Castle Island, expanding South Boston down to Fort Point Channel; this work was completed in the 1920s. Once you’re done enjoying Fort Independence and Castle Island, continue the loop along the Head Island Causeway which circles around Pleasure Bay and completes 2.5 mile walk.

Walkway around Pleasure Bay from Castle Island
Walkway around Pleasure Bay from Castle Island