Fortifications

Fort Farnsworth (1862-1865) - A U.S. Civil War Fort first established as Redoubt B of Fort Lyon in 1862 in present day Alexandria, Fairfax County, Virginia. Named Fort Farnsworth in September 1863 after Brigadier General Elon J. Farnsworth, 8th Illinois Cavalry, who was killed at Gettysburg on 3 Jul 1863.  

Established in 1862 as one of four redoubts in advance of Fort Lyon. After the battle at Gettysburg all four redoubts were were renamed for Union officers killed at that battle. The four newly created forts were Fort Weed, Fort Farnsworth, Fort O'Rourke and Fort Willard. Together with Fort Lyon these forts created a line across the southern approaches to the city of Alexandria.

Fort Farnsworth (originally Redoubt B of Fort Lyon (3)|Fort Lyon]]) was built by elements of the 34th Massachusetts Infantry under the direction of Captain William Bacon. The original redoubt was built with a perimeter of 255 yards enclosing one magazine, a bombproof and emplacements for 13 guns. Armament included four 24 pounders, two 12 pounder howitzers, four 4.5 inch ordnance rifles (2 vacant platforms).  ( Source - Fortwiki )