Potomac. Upon arriving in Washington, McClellan was appalled by the condition of the city's defenses. "In no quarter were the dispositions for defense such as to offer a vigorous resistance to a respectable body of the enemy, either in the position and numbers of the troops or the number and character of the defensive works... not a single defensive work had been commenced on the Maryland side. There was nothing to prevent the enemy shelling the city from heights within easy range, which could be occupied by a hostile column almost without resistance." To remedy the situation, one of McClellan's first orders upon taking command was to greatly expand Washington's defenses. At all points of the compass, forts and entrenchments would be constructed in sufficient strength to defeat any attack. One area of particular concern was the region of Maryland south of the Anacostia River. Confederate artillery floated across the Potomac in secret and mounted south of the river could threaten the Washington Navy Yard and Washington Arsenal, both of which lay at the junction of the Potomac and Anacostia Rivers. To prevent that threat from coming to pass, Brig. Gen. John G. Barnard, chief engineer of the defenses of Washington, directed that a line of forts be constructed on the heights southeast of the Anacostia River. From Fort Greble at the western end to Fort Mahan at the eastern end, the forts along the Eastern Branch River (as the Anacostia was then known) were not intended to constitute a continuous defensive line as was the Arlington Line that defended the Virginia approaches to the city. Instead, they were merely intended to deny Confederate artillery the position and warn of any sneak attack upon Washington from the southeast. General Barnard illustrated this in an October 1862 report, saying, "As the enemy cannot enter the city from this direction, the object of the works is to prevent him seizing these heights, and occupying them long enough to shell the navy-yard and arsenal. For this, the works must be made secure against assault, and auxiliary to this object is the construction of roads by which succor can be readily thrown to any point menaced." Fort Stanton, located in the Garfield Heights, was the first fort of this line to begin construction. Begun in September 1861, the fort was located almost directly south of the Washington Navy Yard and the Navy Yard Bridge