within the boundaries of the Fort Donelson National Battlefield described in section 428p(b) of this title; and

outside such boundaries if the land has been identified by the American Battlefield Protection Program as part of the battlefield associated with Fort Donelson or if the Secretary otherwise determines that acquisition under subsection (a) will protect critical resources associated with the Battle of Fort Donelson in 1862 and the Union campaign that resulted in the capture of Fort Donelson.