Gettysburg National Military Park was established by Act of Congress approved February 11, 1895, authorizing the Secretary of War to receive the lands and improvements of the Gettysburg Battlefield Memorial Association, a corporation chartered by Pennsylvania in 1864 to acquire additional battlefield land for park purposes within the mapped limits prepared by Major-Gen Daniel E. Sickles U.S.A. and filed in the office of the Secretary of War. Subject to the Secretary of War's supervision and direction, the park was placed in charge of commissioners previously appointed under the Act of Congress approved March 3, 1893, and their successors. The commissioners were directed to ascertain and definitely mark the battle lines of all troops engaged at Gettysburg within or adjacent to the park, subject to the Secretary of War's approval. Pursuant to the 1895 act, 522 1/4 acres were conveyed by the Gettysburg Battlefield Memorial Association to the United States. The Secretaries of War under whose approval the work was done were Daniel S. Lamont, Russell A. Alger, Elihu Root, and Wm. H. Taft. The commissioners were Lieut. Colonel John P. Nicholson of Pennsylvania, chairman, John B. Bachelder of Massachusetts, and Brig-General Wm. H. Forney of Alabama; after Forney died January 16 1894, Major Wm. M. Robbins of North Carolina was appointed March 13 1894; after Bachelder died December 22, 1894, Major Charles A. Richardson of New York was appointed April 25, 1895; after Robbins died May 3, 1905, Major-Gen. Lunsford L. Lomax of Virginia was appointed May 17, 1905. The engineering staff included Lieut. Colonel E. B. Cope, Engineer S. Aug. Hammond, Asst.-Engineer, and Hays W. Mattern, Draughtsman.