To facilitate the administration of two areas of the national park system, known as Ackia Battleground National Monument, Mississippi, and Meriwether Lewis National Monument, Tennessee, those areas are included in the Natchez Trace Parkway, which they adjoin; and they shall be administered as a part of the parkway. In order to provide continued recognition of the significance of these portions of the parkway, the Secretary of the Interior shall provide them with appropriate designations in accordance with the historical events which occurred on them.