morality. Though this interpretation was abandoned by the Beards in the 1940s, and by historians generally by the 1950s, Beardian themes still echo among Lost Cause writers. Battlefield preservation The first efforts at Civil War battlefield preservation and memorialization came during the war itself with the establishment of National Cemeteries at Gettysburg, Mill Springs and Chattanooga. Soldiers began erecting markers on battlefields beginning with the First Battle of Bull Run in July 1861, but the oldest surviving monument is the Hazen Brigade Monument near Murfreesboro, Tennessee, built in the summer of 1863 by soldiers in Union Col. William B. Hazen's brigade to mark the spot where they buried their dead following the Battle of Stones River. In the 1890s, the United States government established five Civil War battlefield parks under the jurisdiction of the War Department, beginning with the creation of the Chickamauga and Chattanooga National Military Park in Tennessee and the Antietam National Battlefield in Maryland in 1890. The Shiloh National Military Park was established in 1894, followed by the Gettysburg National Military Park in 1895 and Vicksburg National Military Park in 1899. In 1933, these five parks and other national monuments were transferred to the jurisdiction of the National Park Service. Chief among modern efforts to preserve Civil War sites has been the American Battlefield Trust, with more than 130 battlefields in 24 states. The five major Civil War battlefield parks operated by the National Park Service (Gettysburg, Antietam, Shiloh, Chickamauga/Chattanooga and Vicksburg) had a combined 3.1 million visitors in 2018, down 70% from 10.2 million in 1970. Civil War commemoration The American Civil War has been commemorated in many capacities, ranging from the reenactment of battles to statues and memorial halls erected, to films being produced, to stamps and coins with Civil War themes being issued, all of which helped to shape public memory. These commemorations occurred in greater numbers on the 100th and 150th anniversaries of the war. Hollywood's take on the war has been especially influential in shaping public memory, as in such film classics as The Birth of a Nation (1915), Gone with the Wind (1939), and Lincoln (2012). Ken Burns's PBS television series The Civil War (1990) is especially well-remembered, though criticized for its historical inaccuracy. Technological significance Numerous technological innovations during the Civil War had a great impact on 19th-century science. The Civil War was one of the earliest examples of an