Mounted Union reenactors drill during ongoing activities commemorating the 150th anniversary of the Battle of Gettysburg, Thursday, June 27, 2013, in Gettysburg, Pa. Union forces turned away a Confederate advance in the pivotal battle of the Civil War fought July 1-3, 1863, which was also the war?s bloodiest conflict with more than 51,000 casualties. (AP Photo/Matt Rourke)