Railroad--Construction 2 Banking law--United States--History 1 Compromise of 1850 1 Gettysburg, Battle of, Gettysburg, Pa., 1863 1 Lumber trade--Pennsylvania--New Hope 1 Mexican War, 1846-1848 1 Mexican War, 1846-1848--Campaigns--Maps 1 more ... Roads--Design and construction 1 Scott, Dred 1 Slavery 1 Spouses--Correspondence--19th century 1 Topographical surveying--United States 1 United States--Latin American relations 1 United States. Army of the Potomac 1 United States. Army. Corps of Engineers--History--19th century 1 Wilmot proviso 1 less ...