An estimated 700,000 Union and Confederate soldiers died in the Civil War between April 1861 and April 1865, and as the death toll rose, the U.S. government confronted the urgent but unplanned need to bury fallen Union troops, helping drive the creation of a national cemetery system. On September 11, 1861, the War Department ordered commanding officers to keep accurate and permanent records of deceased soldiers, required the U.S. Army Quartermaster General to mark each grave with a headboard, and soon mandated burial in graves marked with numbered headboards and recorded in a register. Authority to create military burial grounds came with an Omnibus Act of July 17, 1862, directing the president to purchase land for national cemeteries for soldiers who died in service, and fourteen national cemeteries were established by 1862. After the war, in October 1865, Quartermaster General Montgomery C. Meigs ordered officers to survey Civil War lands to locate Union dead and plan their reinterment in new national cemeteries, with sites chosen at camps, hospitals, battlefields, and railroad hubs where troops had been concentrated. By 1872, seventy-four national cemeteries and several soldiers' lots held 305,492 remains, about 45 percent of them unknown, and in the Act to Establish and to Protect National Cemeteries of February 22, 1867, Congress funded permanent walls or fences, grave markers, and lodges for cemetery superintendents. At first only soldiers and sailors who died during the Civil War were buried in national cemeteries, but in 1873 eligibility expanded to all honorably discharged Union veterans, Congress appropriated $1 million to mark graves, upright marble headstones identified known individuals, six-inch-square markers marked unknowns, and military post cemeteries on the Western frontier joined the system. The National Cemeteries Act of 1973 transferred eighty-two Army cemeteries, including twelve of the original fourteen, to what is now the National Cemetery Administration. The country also reflected on the war's human toll, with 2 percent of the U.S. population dead, as memorials donated by regimental units, state governments, and veterans' organizations were erected in national cemeteries, Decoration Day began in 1868 as a popular patriotic spring observance, and by 1920 more than 120 monuments had been placed in the cemeteries.