The principal parts of the 1861 fort are identified in the following list. Each is keyed by number to the illustration. The cutaway section of the illustration shows the arched first- and second-tier casemates behind the brick exterior. The second-tier casemates were unfinished and no cannon were mounted there. [Illustration: Fort Sumter, Aerial view] 1/Left Face 2/Left Flank, facing Charleston and Fort Johnson. 3/Right Face, fronting Fort Moultrie across the main ship channel. 4/Right Flank, facing the Atlantic Ocean. 5/Gorge Wall, facing Confederate batteries on Morris Island. 6/Left Gorge Angle 7/Right Gorge Angle, where Capt. Abner Doubleday commanded a Federal gun crew in one of the lower casemates. 8/Officers’ Quarters, consisting of several three-story apartments for officers and their families. Ordnance storerooms and a hospital were also located here. 9/Enlisted Men’s Barracks, each designed to accommodate two companies. 10/Stair Tower, providing access to the barbette tier. 11/Hot Shot Furnace 12/Second Tier Embrasures 13/Fort Lantern 14/Bins containing oyster shells probably used in the fort’s construction. 15/Sand and Brick-bat Traverses, erected by Federal engineers as protection against Confederate cannon fire. 16/Sandbag Traverse, built to protect Federal gunners against enfilading fire from Fort Moultrie. 17/Machicoulis Gallery, a wooden outcropping atop the parapet in which soldiers could stand to fire into or drop grenades onto an attacking force. 18/Sally Port 19/Granite Wharf Plans for Fort Sumter were drawn up in 1827 and adopted on December 5, 1828. In the course of that winter Lt. Henry Brewerton, Corps of Engineers, assumed charge of the project and commenced active operations. But progress was slow, and as late as 1834 the new fort was no more than a hollow pentagonal rock “mole” two feet above low water and open at one side to permit supply ships to pass to the interior. Meanwhile, the fort had been named Sumter in honor of Thomas Sumter, brigadier general commanding South Carolina militia during the Revolution.