Notwithstanding the provisions of the Act of June 11, 1940 (54 Stat. 262), as amended (16 U.S.C. 261-265 ¹ ), the Secretary of the Interior is authorized to acquire by donation, purchase with donated or appropriated funds, or exchange not to exceed 60 acres of land or interests in land located in Bell County, Kentucky, and Claiborne County, Tennessee, for addition to and inclusion in the said national historical park which, upon acquisition, shall become a part of the Cumberland National Historical Park subject to the laws, rules, and regulations governing such park.