In order to preserve for the benefit and inspiration of the public certain lands historically associated with the winter encampment of General George Washington’s Continental Army at Jockey Hollow in 1779 and 1780, and to facilitate the administration and interpretation of the Morristown National Historical Park, the Secretary of the Interior is authorized to procure, from a willing owner only, by purchase, donation, purchase with appropriated funds, or otherwise, not to exceed 715 acres of land and interests therein which 715 acres shall include Stark’s Brigade campsite and other lands necessary for the proper administration and interpretation of the Morristown National Historical Park: Provided, That title to the property known as the Cross estate may not be accepted until the property is vacant.