In addition to any other lands or interest authorized to be acquired for inclusion in Morristown National Historical Park, and notwithstanding the first proviso of
section 409 of this title, the Secretary of the Interior may acquire by purchase, donation, purchase with appropriated funds, or otherwise, not to exceed 15 acres of land and interests therein comprising the property known as the Warren Property or Mount Kimble. The Secretary may expend such sums as may be necessary for such acquisition.