In 1867, Congress enacted legislation requiring that all military cemeteries be fenced. Meigs ordered the construction of a red Seneca sandstone wall around the cemetery. The construction of the wall (which would not be complete until 1897) necessitated the construction of gates as well.[12] Construction began on a memorial to Major General George B. McClellan (the McClellan Gate) in 1870, but delays in obtaining high-quality red Seneca sandstone delayed its completion until 1879.[13]