Spouses--Correspondence--19th century 3 Gettysburg, Battle of, Gettysburg, Pa., 1863 2 United States. Army of the Potomac 2 United States. Army. Corps of Engineers--History--19th century 2 Antietam, Battle of, Md., 1862 1 Appomattox Campaign, 1865 1 Chinese Americans 1 more ... Hydrographic surveying--Mississippi River 1 Mexican War, 1846-1848--Campaigns--Maps 1 Military Order of the Loyal Legion of the United States 1 Nez Perce Indians--Wars, 1877 1 Seminole War, 2nd, 1835-1842 1 Sioux nation 1 Topographical surveying--United States 1 United States. Army. Corps of Engineers 1 less ...