Fort Arnold/Fort Clinton
View east across Hudson from east side of Fort Arnold/Clinton.
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Constitution Island Fortifications

West Point Fortifications

The Great Chain 

Hudson River


 Sources and Author's Note  


West Point Fortifications Staff Ride Note Cards 30
USMA History Department 2d Edition, March 1998
Fort Clinton (Arnold) (Card #1)
ï Originally known as Fort (James) Clinton after the colonel of the regiment which had constructed it;
McDougall named the fort ìArnoldî in April 1778 after hero Benedict Arnold possibly to antagonize the incoming commander of the Highlands, Horatio Gates, a former foe of Arnoldís dating to the Saratoga campaign. Renamed Fort Clinton after Arnoldís treason in 1780.
ï Purpose: Defend the water batteries protecting the chain for up to 14 days until a relieving force for Continentals and/or militia could arrive.
ï Background
- Following British withdrawal on 20 Oct 1777 , patriots reoccupied, but debated location for new defenses
- Captain Louis de la RADIERE, new French engineer assigned to assist Israel Putnam (Highlands Commander), wanted to refortify S. . . better suited to resisting siege because rocky soil would prevent digging parallels and plain at WP supported siege operations (incorrect application of Vaubanís principles)
- Overruled by Washington siding with American officers. . . selected West Point in Jan 78
-- Plain provided earth needed for walls and good roads for moving construction materials, 300
yards less chain required, and many access points for relief force
-- Toughest part of river
- Garrisoned by regiment from Parsonís brigade in Jan 1778. . .constantly manned ever since.

Sketch of Ft. Clinton by de la Radiere, March 1778
West Point Fortifications Staff Ride Note Cards 31
USMA History Department 2d Edition, March 1998

Fort Clinton (Arnold) (Card #2)
ï Radiere planned Vauban-style fortress with masonry lined walls to prevent deterioration, covered way and glacis (too expensive and time-consuming). 
-Parsons (cdr after Israel Putnam) and George Clinton (NY Governor) recommended simpler field fortifications to be ready by spring in time to protect the chain. 

- Construction began 12 Mar 1778 with priority to S and W walls and SW bastion
ï McDougall named new Highlands commander (Parsons remained garrison commander), with complete authority, and Kosciusko replaced Radiere in April 1778 - better relationship with Americans
ï Kosciuszkoís modifications to Radiereís plan
- added Lanthorn Battery (Geeís Point) and South Battery
- Modified plan for Fort Arnold to reflect Parsonís desires for cheaper, earthen works and to add barracks and magazines within the walls
ï Construction
- Top priority W and S walls built to protect against land approach, H: 9í, D: 20í, ditch 24í base and 34í top. . . dirt for walls came from ditch
- N and E walls built on cliff face, 2 1/2í high and 10í thick to defend against infantry attack from the river and support fire on ships

West Point Fortifications Staff Ride Note Cards 32
USMA History Department 2d Edition, March 1998

view of remnants of east face of Fort Clinton parapet looking south. 
Note angled Vauban-style bastion.
Fort Clinton (Arnold) (Card #3)
- Glacis provides grazing fire from fort on to plain facing west
- All walls no longer than 240 yards (effective range of artillery against infantry)
- Mounted 8 cannon in 4 pairs of embrasures; 4 in SW, 2 ea. in NW and SE for crossfire
- two cannon in each of the flanks of the SW bastion (en barbette)
- two cannon in flanks of demibastions in NW and SE corners (en barbette)
- embrasures were 2í on inside and 9í on outside
- Gate in W curtain 3-4î thick with small door (3í) cut into it
- Chevaux-de-frise on bridge 4í in front of gate and at far end; fraise above gate

- Also contained storehouse, powder magazine, guard house, commissary, and well
ï Manpower: 600 men in two story barracks, 19íx19í (18 beds, 2 men per bed, 3í wide)
ï Problems
- Lack of artillery required water batteries to remain unmanned
- Maintenance. 1780 ìBlack Yearî saw fortifications in worst state of repair due to bad weather
and Arnoldís deliberate neglect, lack of materials, sickness, and weather. Latter three conditions
remained problems throughout history of fort.
ï Fort Clinton and water batteries completed by Nov 1780 under Kosciuskoís replacement, Major
Villefranche. Sherbourneís redoubt was not repaired because it was deemed unnecessary
ï Still needed significant work as late as 1782
ï Post-Revolution History: Used by Military Academy for engineering and artillery instruction

This page maintained by Erik Riker-Coleman
Last updated some time ago...