New Philadelphia, Illinois, Study Act - Directs the Secretary of the Interior to conduct a special resource study of the New Philadelphia archaeological site and the land surrounding it in Illinois (the study area).
Requires the Secretary to: (1) evaluate the national significance of the study area; (2) determine the suitability and feasibility of designating the study area as a unit of the National Park System; (3) consider other alternatives for the preservation, protection, and interpretation of the study area and identify the costs associated with such alternatives; and (4) consult with specified public and private entities.
Requires the Secretary to report to Congress on the study's results, as well as any conclusions and recommendations of the Secretary.