In addition to Virginia and Confederate government offices and hospitals, a railroad hub, and one of the South's largest slave markets, Richmond had the largest factory in the Confederacy, the Tredegar Iron Works, which turned out artillery and other munitions, including the 723 tons of armor plating that covered the CSS Virginia, the world's first ironclad used in war, as well as much of the Confederates' heavy ordnance machinery. The Confederate Congress shared quarters with the Virginia General Assembly in the Virginia State Capitol, with the Confederacy's executive mansion, the "White House of the Confederacy", located two blocks away. The Seven Days Battles followed in late June and early July 1862, during which Union General McClellan threatened to take Richmond but ultimately failed.

What was the name of the biggest factory in the Confederate States of America?