170519-N-BX824-050 GETTYSBURG, Pa. (May 19, 2017) John Heisser, historian at Gettysburg National Military Park, gives Sailors assigned to the United States Navy Ceremonial Guard a tour of the battlefield prior to a community relations project. The USNCG participated in the COMREL to conserve and preserve the site of the Civil War-era Battle of Gettysburg, fought between Union and Confederate forces from 1-3 July, 1863. (U.S. Navy photo by Mass Communication Specialist 3rd Class Ricky Guzman/Released)