Fortification constructed of timber, muskets and cann0n fire from within.

Blockhouse

Fortification constructed of timber, muskets and cann0n fire from within.

Blockhouses, built of heavy logs with the second story overhanging the first, were created for defense against enemies.

Blockhouse

Blockhouses, built of heavy logs with the second story overhanging the first, were created for defense…

An illustration of a castle.

Castle

An illustration of a castle.

A large, circular Chinese encampment.

Chinese encampment

A large, circular Chinese encampment.

"View of the Fort Euryalus at Syracuse." — Smith, 1882

Fort Euryalus

"View of the Fort Euryalus at Syracuse." — Smith, 1882

"Fort built around the officer's quarters of the First Minnesota Regiment, Colonel Sully, near Fair Oaks, VA. The peculiarities of the States and nationalities as were represented in the Federal Army developed themselves in a variety of ways. At Fortress Monroe the German regiments erected bowers in which they quaffed their lager and smoked, while their regimental bands played airs which led them back by the ear to Das Vaterland; and the Garibaldi Guard made their tents as much like Swiss cottages as possible. The First Minnesota Regiment, Colonel A. Sully, little dreaming how soon they would have to abandon their handiwork to the enemy, erected a fort around the commodious farm house near Fair Oaks, which, after the battle of Seven Pines, May 31st, 1862, had been given to their captains and lieutenants for their quarters. The appearance was so strange that an officer of General McClellan's staff made a sketch and sent it to us." — Frank Leslie, 1896

First Minnesota Regiment

"Fort built around the officer's quarters of the First Minnesota Regiment, Colonel Sully, near Fair…

The fort held by Spain in St. Augustine, Florida.

Spanish Fort in St. Augustine, Florida

The fort held by Spain in St. Augustine, Florida.

Fort Chambly at the foot of the Chambly rapids on the Richelieu River in Quebec, Canada, was built by the French in 1711.

Fort Chambly

Fort Chambly at the foot of the Chambly rapids on the Richelieu River in Quebec, Canada, was built by…

Groups of people gathered on the shores of a river.

Fort Donelson After Its Surrender

Groups of people gathered on the shores of a river.

An illustration of Fort Jefferson which is located today in what is Dry Tortugas National Park. Dry Tortugas National Park preserves Fort Jefferson and the Dry Tortugas section of the Florida Keys. The park covers 101 mi² (262 km²), mostly water, about 68 statute miles (109 km) west of Key West in the Gulf of Mexico.

Fort Jefferson

An illustration of Fort Jefferson which is located today in what is Dry Tortugas National Park. Dry…

Fort Michilimackinac or Fort Mackinaw was an 18th century French, and later British, fort and trading post in the Great Lakes of North America.

Fort Mackinaw

Fort Michilimackinac or Fort Mackinaw was an 18th century French, and later British, fort and trading…

"Surrender of Fort Macon, GA., April 26th, 1862. Exterior on side facing the Federal Batteries, showing effect of shot on the glacis and walls." — Frank Leslie, 1896

Fort Macon

"Surrender of Fort Macon, GA., April 26th, 1862. Exterior on side facing the Federal Batteries, showing…

The attack on Fort Moultrie, South Carolina.

Attack on Fort Moultrie

The attack on Fort Moultrie, South Carolina.

Fort Sumter after its bombardment.

Fort Sumter

Fort Sumter after its bombardment.

An illustration of the defense at Fort Sumter.

Defense at Fort Sumter

An illustration of the defense at Fort Sumter.

The fort was built by the British Army and Canadian militia troops in the late eighteenth and early nineteenth centuries, to defend the settlement and the new capital of the Upper Canada region from the threat of a military attack, principally from the newly independent United States.

Fort York

The fort was built by the British Army and Canadian militia troops in the late eighteenth and early…

A fortified building situated between two sharp hills at the edge of a lake. Two men are launching a boat.

Fortification

A fortified building situated between two sharp hills at the edge of a lake. Two men are launching a…

Depiction of the battle on the Mississippi between Confederate and Union forces at Forts Jackson and St. Philip.

Passage of Forts Jackson and St. Phillip

Depiction of the battle on the Mississippi between Confederate and Union forces at Forts Jackson and…

Fort Pickens is a pentagonal historic United States military fort on Santa Rosa Island in the Pensacola, Florida area.

Forts Pickens and McRae

Fort Pickens is a pentagonal historic United States military fort on Santa Rosa Island in the Pensacola,…

"Headquarters of General Butterfield, near Harrison's Landing, James River, Va." —Leslie, 1896

Headquarters of General Butterfield

"Headquarters of General Butterfield, near Harrison's Landing, James River, Va." —Leslie, 1896

View of the camp of the twentieth Indiana Regiment; also of Fort Hatteras and the anchorage at Hatteras inlet, N.C. This camp, was formed when Federal troops occupied the island. It first recieved Colonel Bendix and his German regiment. On their return to Newport News it was taken possession of by the Ninth Zouaves; who vacated it upon the arrival of the Twentieth Indiana Regiment, October 5, 1861, the Ninth removing to Camp Wool.

Fort Hatteras

View of the camp of the twentieth Indiana Regiment; also of Fort Hatteras and the anchorage at Hatteras…

A drawing of a brutal attack on an Iroquois fort.

Attack on an Iroquois Fort

A drawing of a brutal attack on an Iroquois fort.

Fort Michilimackinac or Fort Mackinaw was an 18th century French, and later British, fort and trading post in the Great Lakes of North America.

Mackinaw from Round Island

Fort Michilimackinac or Fort Mackinaw was an 18th century French, and later British, fort and trading…

Fort Pulaski, on Cockspur Island at the entrance to the Savannah River, Georgia, was built by the United States Government in 1829-31, for the defense of Tybee Roads and the Savannah River approach to the city of Savannah, Georgia. In January, 1861, it was seized and occupied by the military authorities of the State of Georgia, and held by them until transferred to the Confederate Government, by whom it was strongly armed and garrisoned. In form it was pentagonal; its walls were forty feet high, and presented two faces on the sea approach. The full armament of the fort consisted on the lower tier of 65 32-pounders, and the upper tier of 53 24-pounders, 4 18-pounders flanking howitzers, 1 13-inch mortar, 12 8-inch columbiads, and 7 10-inch mortars. The interior of the fort was well supplied with massive furnaces for heating shot, officers' quarters, soldiers' barracks, magazines, and a tolerable supply of shot and powder.

Fort Pulaski

Fort Pulaski, on Cockspur Island at the entrance to the Savannah River, Georgia, was built by the United…

"View of Rolla, Mo., taken from the fort." —Leslie, 1896

Rolla

"View of Rolla, Mo., taken from the fort." —Leslie, 1896

"Encampment of the Federal army near Rolla, Mo. The city of Rolla has been famous since the death of heroic Lyon, when the scattered forces of that glorious but disastrous day, under the guidance of General Siegel, made their first secure resting place. Our illustration is particularly interesting, as it takes in the last encampment of the Federal Army, showing the positions of the chief divisions of Generals Asboth, Siegel and Wymans. Rolla is on the direct route of the railroad from St. Louis to Springfield, being about midway between those cities. It is about sixty miles from Pilot Knob and fifty from Jefferson City. Our artist said: "The high rolling country around Rolla is admirably adapted for a camping ground. Fine streams of clear water intersect in all directions; the ground is gravelly and dry, and all the hills are covered with oak timber. The camping grounds are all gently sloping, facing the south, and are well protected from the cold north and northwest winds by the high ridges on the north."" —Leslie, 1896

Rolla camp

"Encampment of the Federal army near Rolla, Mo. The city of Rolla has been famous since the death of…

In military affairs, a narrow ditch or trench by which approach is made to a fortress or designed place when within range of fire. This is a section of covered sap.

Covered Sap

In military affairs, a narrow ditch or trench by which approach is made to a fortress or designed place…

In military affairs, a narrow ditch or trench by which approach is made to a fortress or designed place when within range of fire. This is a double sap on the serpentine plan.

Double Sap

In military affairs, a narrow ditch or trench by which approach is made to a fortress or designed place…

In military affairs, a narrow ditch or trench by which approach is made to a fortress or designed place when within range of fire. This is sap on a rectangular plan.

Rectangular Sap

In military affairs, a narrow ditch or trench by which approach is made to a fortress or designed place…

In military affairs, a narrow ditch or trench by which approach is made to a fortress or designed place when within range of fire. This is a section of single sap, showing portion of gabions.

Single Sap

In military affairs, a narrow ditch or trench by which approach is made to a fortress or designed place…

The first non-Native American community in the California Central Valley.

Sutter's Fort

The first non-Native American community in the California Central Valley.

Tower of London, with donjon in courtyard.

Tower of London

Tower of London, with donjon in courtyard.

The Western Battery was built by the British Army. With ample supply of trees from the surrounding area it was made of wood. It had two guns with a blockhouse.

Remains of the Western Battery in 1860

The Western Battery was built by the British Army. With ample supply of trees from the surrounding area…