Named for Confederate Senator Gustavus Henry of nearby Clarksville, this poorly positioned earthen field fortification was laid out on low ground by Tennessee state engineers and constructed in the summer of 1861 to defend the Tennessee River and the critical railroad route between Bowling Green, Kentucky, and Memphis. The fort, with its seventeen mounted guns and an adjacent entrenched garrison camp, became the scene of the first major Union victory in the western theater on February 6, 1862. Fewer than 3,400 ill-equipped Confederate soldiers under the command of Brigadier General Lloyd Tilghman manned the fort, which was largely inundated by floodwaters. Brigadier General Ulysses S. Grant commanded 15,000 troops supported by Flag Officer Andrew H. Foote's seven gunboats.
Tilghman quickly recognized the futility of his position and sent all but 70 artillerymen overland to reinforce nearby Fort Donelson. Foote's gunboats led the attack, and Grant's army moved by land to surround the garrison. The navy's heavy and accurate firepower quickly overcame the defenders, whose antiquated cannon proved ineffective. Foote and his officers simply rowed through the sally port of the half-submerged fort to receive Tilghman's “unconditional surrender,” the first of the war. They found a wrecked fort and tallied Confederate losses at five dead, eleven wounded, and the remainder captive. Tilghman and his men remained in Northern prison camps until exchanged six months later. The Union forces sustained casualties of eleven killed, thirty-one injured, and five missing.
The victory at Fort Henry belonged to the navy; Grant's foot soldiers, delayed by weather and muddy roads, did not join the fighting. With surprising ease, Foote breached the Confederate line and opened the Tennessee River to northern Alabama. Within days of Fort Henry's surrender, three gunboats raided 150 miles upstream to Muscle Shoals, destroying bridges and boats and uncovering ostensible pockets of Unionist sentiment among inhabitants along the way. Here was a spectacular demonstration of strategic military power. Moreover, Grant soon moved his land army to besiege and capture Fort Donelson, further opening the route of invasion into Tennessee and the upper Confederate heartland.
With the fall of Fort Henry, Union forces outflanked the major Confederate defensive bastion at Columbus, Kentucky, on the Mississippi River and opened West Tennessee to Union invasion and occupation. Fort Henry spawned the temporary myth of gunboat superiority over land defenses (partly offset soon by actions at Fort Donelson) and suggested a potent weapon in the hands of the Union, one for which the Confederates had little defense. Fort Henry demonstrated that the Civil War in the West would be fought largely for control of the rivers–antebellum commercial arteries that became wartime barriers to effective Confederate unity and Union avenues for military, political, and economic reconstruction. The site of Fort Henry now lies beneath the waters of Kentucky Lake, although outworks remain at Land Between the Lakes.
Benjamin Franklin Cooling, Forts Henry and Donelson: The Key to the Confederate Heartland (1987) and Fort Donelsons Legacy: War and Society in Tennessee and Kentucky, 1862-1863 (1997)