SHARPSBURG, MD - Inmates are preserving some local history and giving back to the community.  They helped donate over 100 tons of rock to the Antietam National Battlefield, a gift park officials couldn't be more thankful for.

It may look like just another pile of rocks, but they're actually helping to preserve about 150 years of American history.

125 tons of stone is helping to restore 14 different projects around the battlefield.  It's a donation that's saving up to $100,000.   Workers are already putting them to good use, restoring the foundation at a barn on the Poffenberger Farm.

The generous gift comes from an unlikely source: the Maryland Division of Corrections.

The stones were hand-cut by inmates in the 1930's, which is about 100 years after the Poffenberger barn was built.  However, they're still almost a perfect match for the foundation.

"These rocks are exactly like the same type of stone that Joseph Poffenberger would have used to build his barn here originally," says John Howard, the battlefield superintendent.  "So it's really like taking a piece of the past and plugging it into a piece of the past that might be broken."

Today's inmates are helping with the project by unloading all the stone from a ground silo at the prison complex to bring them to the battlefield.

Secretary Gary Maynard with the Department of Public Safety and Correctional Services adds, "This may make a difference to some inmates.  They may, because of this project, become involved with history and know more about our country and where we came from."

The stones were actually leftovers from when the Maryland Correctional Institution in Hagerstown was being built.  They sat unused in a ground silo for decades.