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 developed a national cemetery system to bury fallen Union troops, requiring accurate records, marked graves, and numbered headboards recorded in registers. Authority to create military burial grounds came with an Omnibus Act of July 17, 1862, and fourteen national cemeteries were established by 1862. After the war, Quartermaster General Montgomery C. Meigs directed officers in October 1865 to locate Union dead across the Civil War theater and reinter them in new national cemeteries, with sites chosen near 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 funded permanent walls or fences, grave markers, and lodges in 1867, and burial eligibility, at first limited to Civil War dead, was expanded in 1873 to all honorably discharged Union veterans. Upright marble headstones marked known individuals, while six-inch-square blocks marked unknowns, and military post cemeteries on the Western frontier joined the system by 1873. 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 war’s human cost, amounting to 2 percent of the U.S. population, also shaped memorialization in these cemeteries, where donated monuments, Decoration Day observances beginning in 1868, and later Memorial Day ceremonies honored the dead; monument building peaked in the 1890s, and by 1920 more than 120 monuments stood in the national cemeteries.