Is Gettysburg National Military Park haunted?
United States Reported haunting level 2 of 5

What actually happened
Three days of fighting from 1 to 3 July 1863 left over 51,000 soldiers dead, wounded or missing, the bloodiest battle of the Civil War.
The history
Robert E. Lee's Army of Northern Virginia met George Meade's Army of the Potomac here in July 1863. Lincoln dedicated the Soldiers' National Cemetery on 19 November 1863 with the Gettysburg Address.
What people report
Visitors have reported figures in period uniform at Devil's Den and Little Round Top who vanish when approached.
That paragraph is reported tradition, not a claim about what is there. The history above it is sourced; the stories are recorded because people tell them.
Visiting
1195 Baltimore Pike, Gettysburg, PA 17325, United States