Today we commemorate the passing of the National Historic Preservation Act. The Act was established to help preserve important historic and archeological sites. Washington's Headquarters at Valley Forge, also known as the Isaac Potts House, is a historic house that is one of the centerpieces of Valley Forge National Historical Park in southeastern Pennsylvania. Built around 1773, General George Washington made his headquarters here during the encampment at Valley Forge of the Continental Army between December 1777 and June 1778. The restored building was designated a @nationalhistoriclandmarknps in 1972 and is also listed on the @nationalregisternps. Established on October 15, 1966, the National Historic Preservation Act was the most comprehensive preservation law the nation had ever known. The act established permanent institutions and created a clearly defined process for historic preservation in the United States. Image: An autumn view of the historic stone building known as Was...