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 struggled with the urgent but unplanned need to bury fallen Union troops, helping propel the creation of a national cemetery system. On September 11, 1861, the War Department directed commanding officers to keep accurate and permanent records of deceased soldiers and required the U.S. Army Quartermaster General to mark each grave with a headboard; a few months later it mandated interment in graves marked with numbered headboards and recorded in a register. Authority to create military burial grounds came in an Omnibus Act of July 17, 1862, which directed the president to purchase land for national cemeteries, and fourteen were established by 1862. After the war, in October 1865, Quartermaster General Montgomery C. Meigs ordered surveys across the Civil War theater to find Union dead and plan their reinterment in new national cemeteries, with sites chosen where troops had been concentrated in camps, hospitals, battlefields, and railroad hubs. By 1872, seventy-four national cemeteries and several soldiers' lots held 305,492 remains, about 45 percent of them unknown. Congress strengthened and protected these burial grounds in the Act to Establish and to Protect National Cemeteries of February 22, 1867, funding 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 there, but in 1873 eligibility expanded to all honorably discharged Union veterans, and Congress appropriated $1 million to mark graves; upright marble headstones honored individuals whose names were known, while 6-inch-square blocks marked unknowns. By 1873, military post cemeteries on the Western frontier had joined the system, and 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 nation also reflected on the war's human toll, with 2 percent of the U.S. population dead; memorials donated by regimental units, state governments, and veterans' organizations rose in these cemeteries, Decoration Day began in 1868 as a spring observance with flowers and speeches, monument building peaked in the 1890s, and by 1920 more than 120 monuments stood in the national cemeteries.