From this position, Union artillery crews could sweep the surrounding valleys,
turnpikes, and river approaches with devastating fire. The fort’s ten angles were
engineered with precision, ensuring that no enemy could approach without being exposed
to infantry and cannon fire.
Historic View
Walking Tour Map
Civil War fortifications were precisely designed. The ten angles of the fort were
engineered to allow infantry and artillery to sweep every inch of ground in front
of the walls. As Captain DeLand wrote, “every gun in the fort will sweep the
turnpikes and rivers with shot and shell for three miles.”
At least one cannon stood behind each of the fort’s ten angles, giving Union soldiers
the ability to deliver all‑around covering fire toward the many back roads and southern
approaches to Fort Duffield. Although the 9th Michigan Infantry was an infantry regiment,
they initially manned their own artillery pieces during the early months of the war.
In March 1862, Captain Charles H. Lamphere’s Battery G, 1st Michigan Light Artillery,
arrived to take over the guns.
The primary weapon used here was the 6‑pound smoothbore cannon, a dependable
field piece ideal for defending steep slopes and open approaches. One rifled cannon
was also present — likely the Stuckey Gun or a similar experimental piece.
Artillery Layout Diagram
North
↑
|
West ←─────────┼─────────→ East
|
↓
South
[ Fort Duffield ]
-------------------------------------------------
| |
| • 10 Angles of Fire |
| • 6‑pound smoothbores behind each angle |
| • 1 rifled cannon (experimental) |
| |
| • Ammunition Bunker (East Interior) |
| • Officers’ Cabins (East Interior) |
| • Enlisted Tents (West Interior) |
| |
-------------------------------------------------
Ammunition Bunker
The ammunition bunker was located on the east interior side of the fort — the safest
position, far from open flames, the cooks’ area, and the latrine. It was dug into the earth,
timber‑lined, and covered with several feet of packed soil to prevent sparks, moisture, and
enemy fire from reaching the powder.
Dimensions
- Length: 25–35 ft
- Width: 10–14 ft
- Interior Height: 7–8 ft
- Earth Cover: 3–6 ft of packed soil
- Construction: Timber walls and roof, clay‑sealed seams, baffled ventilation
This produced roughly 2,000–3,500 cubic feet of usable interior space, depending on
walkway vs. stacked storage.
Ammunition Capacity
- 600–1,000 rounds total for the fort’s artillery
- Separate storage bays for powder kegs and projectiles
- Friction primers stored in a sealed, spark‑proof container
Powder Storage
- 1,000–1,250 lb of powder
- 40–50 kegs of black powder
- Each 6‑pounder charge used 1.0–1.25 lb of powder
Projectile Types
- Solid Shot: round iron balls for smashing fences, wagons, and fortifications
- Case Shot: thin‑walled shells filled with musket balls and a timed fuse
- Canister: tin can filled with iron balls — a giant shotgun blast
- Rifled Shells: elongated projectiles used only in the rifled cannon
Why Soldiers Mentioned 6 or 7 Guns
Letters from the 9th Michigan vary between six and seven cannons.
This is normal for early‑war forts. The number changed because:
- Guns arrived at different times
- One rifled cannon was experimental and not always counted
- Some letters were written before all guns were mounted
- Artillery was sometimes temporarily moved for testing or repair
By early 1862, the fort had ten angles of fire and enough artillery to cover them,
though not every angle always had a gun mounted at the same time.
Artillery FAQ
How many cannons were at Fort Duffield?
By early 1862, the fort had ten angles of fire and enough artillery to cover them,
including one rifled cannon.
Where was the ammunition stored?
the safest location, far from open flames and prevailing winds.
What kinds of projectiles were used?
The rifled cannon fired elongated shells with greater accuracy.
What Happened Here
a. Ten Angles of Fire
Fort Duffield is a thousand‑foot‑long earthen wall with ten angles of fire. The most
common cannon used here was the 6‑pound smoothbore. At least one gun was
positioned behind each angle to provide all‑around covering fire toward the many back
roads south of the fort.
b. Dimensions of the Wall
According to a letter by Capt. Charles V. DeLand, the distance from the top of the wall
to the bottom of the ditch was 17 feet. The top of the wall was 9 feet wide.
Time has eroded the walls to their present height and thickness, but the original scale
was formidable.
c. Precision Engineering
Civil War fortifications were not random piles of earth. Every angle, slope, and mound
at Fort Duffield served a purpose. The ten angles ensured there were no “dead spaces”
where an attacker could hide. As Captain DeLand wrote, “every gun in the fort will sweep
the turnpikes and rivers with shot and shell for three miles.”
d. Unique Shape of the Fort
Unlike the octagonal or star‑shaped forts common at the time, Fort Duffield’s wall was
shaped somewhat like a letter W and open on the rear (facing West Point). The
300‑foot cliff behind the fort made a rear wall unnecessary and provided natural
protection. This unusual shape allowed the fort to conform to the ridge while maximizing
defensive coverage.
e. Artillery Crews
Although the 9th Michigan Infantry was not an artillery unit, they manned their own guns
until relieved by Battery G, 1st Michigan Light Artillery under Captain Charles H.
Lamphere in March 1862.
f. Gate Security
Large timbered gates stood at both ends of the thousand‑foot wall. These gates hugged the
cliff to maximize protection. The fort was considered so secure that when locks were
requested, the quartermaster jokingly sent two toy locks.
g. “As Secure as a Nest of Young Eagles”
Captain DeLand wrote that the men felt “as secure as a nest of young eagles in our new
fort,” a testament to the strength and engineering of the defenses.
h. Life on the Ridge
On December 5th, 1861, DeLand wrote: “Our new camp upon the mountain is a paradise to
what we have enjoyed for the past four weeks, and pure air and water are showing their
invigorating effects upon the men daily, almost hourly.”
The fort was fifteen rods deep and about forty rods in a straight line from right to
left — but nearly eighty rods when following all the angles. A deep ditch surrounded the
walls, and the fort could mount ten cannons and house 1,000 men. When the 9th Michigan
arrived, a cornfield occupied the hilltop, but the surrounding trees were quickly cut
down to give the guns a clear field of fire.