The town of Thurmont in the U.S. state of Maryland is located on U.S, Route 15 between Frederick to the south and Gettysburg, Pennsylvania to the north. The town’s claim to fame is the home of Camp David, the famous retreat of the President of the United States of America. (Camp David is not open to the public.) Just south of this town is the ruins of an old iron furnace known as the Catoctin Iron Furnace. The furnace gets its name from nearby Catoctin Mountain. What is special about these ruins? Well, of course, it was once a working iron furnace. It was originally owned by Thomas Johnson and his brothers. Who was Thomas Johnson? He was the former governor of the U.S. state of Maryland. It was here where shells were made and sent to Yorktown, Virginia and were used to secure the victory for the United States…