The purpose of this legislation is to expand the boundaries of the Marsh-Billings-Rockefeller National Historical Park in Vermont. It aims to enhance the park's historical and environmental significance while providing better access and opportunities for education and conservation. Key provisions of the legislation include a detailed description of the new boundaries for the park, which will now encompass a historic zone featuring the Marsh-Billings-Rockefeller Mansion and surrounding buildings, as well as a protection zone that includes the Billings Farm and Museum.