Fort Donelson National Battlefield Expansion Act of 2003

Fort Donelson National Battlefield Expansion Act of 2003 - Authorizes the Secretary of the Interior to acquire for inclusion in the Fort Donelson National Battlefield land, interests, and improvements: (1) within the boundaries of the Battlefield; and (2) 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 will protect critical resources associated with the Battle of Fort Donelson in1862 and the Union campaign that resulted in the capture of the Fort. Limits the total area encompassed by the Battlefield to 2,000 acres.Directs the Secretary and the Secretary of Agriculture to enter into a memorandum of understanding to facilitate cooperatively protecting and interpreting the remaining vestige of Fort Henry and other existing Civil War resources affiliated with the Fort Donelson campaign and located in the Land Between the Lakes National Recreation Area.