16 U.S.C. § 430f–9

(a) In general The Secretary may acquire land and interests in land within the boundary of the Park described in section 430f–8(b) of this title , by— (1) donation; (2) purchase with donated or appropriated funds; or (3) exchange. (b) Exception Land may be acquired only by donation from— (1) the State of Mississippi (including a political subdivision of the State); (2) the State of Tennessee (including a political subdivision of the State); or (3) the organization known as “Friends of the Siege and Battle of Corinth”.