Washington, A Capital Without Defences
With the outbreak of the American Civil War, Washington, DC turned into the training ground, arsenal, supply depot, and nerve centre for the Union cause. Newly formed regiments encamped in every quarter, and streets reverberated under the wheels of cannons. Cattle for meat grazed on the National Mall; sacks of flour, stacked against siege, surrounded the U.S. Treasury. To protect the city and vital supply routes from enemy hands, Union armies built a ring of earthen fortifications.
In the spring of 1861 the city lay open to attack by states that withdrew from the Union. Virginia, just across the Potomac, seceded in April. Maryland, a slave state, had many southern sympathizers. They answered President Lincoln's call for volunteers by burning bridges and tearing tracks to prevent Union soldiers from reaching the capital. In spite of hostile acts, enough regiments arrived to seize and fortify footholds across the river in Virginia, occupying points from below Alexandria to hills above Chain Bridge, including the Arlington plantation of the Robert E. Lee family. This move placed offices of the federal government beyond the reach of Confederate cannons.
When the Civil War began, only one fortification existed for the capital's defence: Outmoded Fort Washington, nearly 12 miles down the Potomac, built to guard against enemy ships following the War of 1812. It took the rout of federal forces at Manassas in July 1861 to reveal how truly vulnerable the city was. Taking command of and reorganizing the Army of the Potomac, Major General George B. McClellan appointed Major (later brevet major general) John G. Barnard of the Corps of Engineers to build many new forts.
Selecting sites a few miles outside the city limits, Barnard's engineers picked high points that overlooked major turnpikes, railroads, and shipping lanes. Natural fords upriver from the city, allowing the enemy to cross the Potomac during low water, spurred the building of more forts and batteries. Rifle pits filled the gaps. By spring 1865, the defence system totalled 68 forts and 93 batteries with 807 cannons and 98 mortars in place. Twenty miles of rifle trenches flanked the bristling strongholds, joined by more than 30 miles of military roads and guns could move as reinforcements. Washington had become the most heavily fortified city in the world.
Fort construction plans followed the standard treatise on field fortifications, though no two forts were exactly alike. Labourers piled up earthworks so that parapets 12 to 18-feet thick faced exposed fronts. Within the ramparts, field and siege guns were mounted on platforms to lay down a wide angle of fire. Outside the earthworks, a steep slope led down to a dry moat. Beyond this ditch, felled trees in front with sharpened branches pointing outward (called an abatis) ringed the fort. Work parties cleared all brush and trees in front of the fort for up to two miles, leaving no cover.
Inside the fort a rounded structure of heavy timbers heaped with 10 or more feet of rammed earth formed the magazine for storing ammunition and kegs of gunpowder. The bombproof, a longer mound, sheltered gun crews and officers. Often the bomb proof's dirt covering was notched to make a bench from which rifleman could fire. Every fort had a well or spring for clean water and a flagstaff to fly the Union colours. The entrance was called the sally port.
The effort to protect the capital continued throughout the war. At first, companies of soldiers worked on the defences before being called to drill and prepare for battle. Later hired labourers--carpenters, teamsters, blacksmiths, and othersmade up the work crews. Of the thousands of contrabands-- fugitives from slavery--that took refuge in the city, hundreds laboured on fortifications and served the garrisons. "None need be idle," reported the Anglo-African newspaper.
Life for enlisted men in the forts began at dawn. Drill, repairs, duties, parades, and inspection consumed the day. "The time passed pleasantly enough," wrote one solder, spared from hardships in the field.
The above article appeared in the ACWS Newsletter, Winter 2011