The Official Records of the War of the Rebellion or often more simply the Official Records or ORs, constitute the most extensive collection of primary sources of the history of the American Civil War. Cornell University lists the official title as, "The War of the Rebellion: a Compilation of the Official Records of the Union and Confederate Armies". They include selected first-hand accounts, orders, reports, maps, diagrams, and correspondence drawn from War and Navy Department records of both Confederate and Union governments.