Fort Montgomery in Orange County, New York — The American Northeast (Mid-Atlantic)
Powder Magazine
Fort Montgomery’s powder magazine provided a secure, dry place in which to store the garrison’s gunpowder and ammunition. The magazine was located here because of the site’s good drainage and because of the protection afforded by the rock ridge between it and the river. The magazine was built early in the fort’s construction. By the middle of June 1776, its 8-foot-thick walls were completed, and masons were ready to finish its arched brick vault. Once finished, the arch was covered with sandy soil and a roof was built over top to finish the magazine.
Some of Fort Montgomery’s powder was produced at Henry Wisner’s powder mill 20 miles away in Goshen, New York. The loose powder was stored in the magazine in 100-pound barrels until it was used to make cartridges for muskets and cannons. This magazine served both Forts Montgomery and Clinton. During the battle, however, the British cut off communication between the two forts by capturing the pontoon bridge. When the British overran Fort Clinton, its garrison was running out of ammunition.
From the platform you are standing on, you can look through the powder magazine’s doorway into the interior of its foundation.
Erected by Fort Montgomery State Historic Site.
Topics. This historical marker is listed in these topic lists: Forts and Castles • Military • Notable Places • War, US Revolutionary. A significant historical year for this entry is 1776.
Location. 41° 19.481′ N, 73° 59.212′ W. Marker is in Fort Montgomery, New York, in Orange County. Marker is on U.S. 9W, on the right when traveling north. Marker is in Fort Montgomery State Historic Site on the walking trail, near Route 9W. Touch for map. Marker is in this post office area: Fort Montgomery NY 10922, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within walking distance of this marker. Guard House (within shouting distance of this marker); Soldiers’ Necessary (within shouting distance of this marker); Fort Montgomery Today (within shouting distance of this marker); Building a Fort (within shouting distance of this marker); The Battle of Fort Montgomery (within shouting distance of this marker); Enlisted Men’s & Officers’ Barracks (about 300 feet away, measured in a direct line); The Naval Battle of Fort Montgomery (about 300 feet away); Grand Battery (about 300 feet away). Touch for a list and map of all markers in Fort Montgomery.
More about this marker. The marker contains a picture of a cross section of the Powder Magazine, with descriptions of its different parts:
"Gabled Roof
The gabled roof and framing details shown here were based on archeological and documentary evidence as well as on 1815 magazine plans from Canada. The roof protected the rest of the structure from the weather, helping ensure that the gunpowder would stay dry.
Sandy Soil
Sandy yellow soil was filled in the area above the brick arch and below the roof. The soil provided a protective layer over the magazine’s vault to absorb the impact of enemy cannon balls.
Brick Vault
An arched, brick vault nearly 4 feet thick was constructed with very hard bricks and was mortared with an extremely hard mortar. The vault was arched to support the weight of the soil above it and was made of brick rather than wood so it would not rot when in contact with the soil. The arched vault also protected the gunpowder in the event the magazine’s roof leaked.
8-Foot-Thick Walls
The magazine’s walls were 8 feet thick, consisting of mortared stones on the interior and exterior with rubble fill in between. The interior stones mortared smooth. The exterior stones were mortared with struck joints to create an edge from which water would drip rather than run into the magazine.
Ventilation
Although not shown in the illustration, the magazine probably had some kind of ventilation in the walls. Ventilation would ensure enough airflow to keep moisture from condensing inside the magazine and spoiling the powder.
Clay Grouting
“Blue clay” grouting was applied along the base of the walls to prevent water from seeping into the magazine.
Wooden Floor
Projecting stones along both side walls and the bedrock in the corners supported sill beams for the framing of the floor. There was a one-foot airspace beneath the floor beams that kept the powder away from any ground moisture.
The picture also labels the Brick Flat Arch.
Under the picture is the caption “Powder Magazine – Fort Montgomery 1776-1777. Conjectural drawing based on archeological and documentary evidence: Jack Mead, 1992.”
Various pictures on the marker had captions of:
“Artillery cartridges were prepared from the bulk gunpowder and were stored in the magazine until a battle was imminent.”[left top]
“Soldiers used the bulk of gunpowder to construct cartridges for their muskets. These cartridges were stored in the magazine.”[left bottom] and
“A typical barrel of gunpowder was 16 inches in diameter, 30 inches tall, and held 100 pounds of powder.”[lower right]
Related markers. Click here for a list of markers that are related to this marker. This series of markers follow the walking tour of the Fort Montgomery Battlefield.
Also see . . . The Battle of Fort's (sic) Montgomery and Clinton. The American Revolutionary War website entry (Submitted on May 6, 2008, by Bill Coughlin of Woodland Park, New Jersey.)
Credits. This page was last revised on August 19, 2021. It was originally submitted on May 6, 2008, by Bill Coughlin of Woodland Park, New Jersey. This page has been viewed 1,419 times since then and 11 times this year. Photos: 1, 2, 3, 4, 5. submitted on May 6, 2008, by Bill Coughlin of Woodland Park, New Jersey. • Kevin W. was the editor who published this page.