National Park Service - Partners with American Indian tribes, states, local governments, nonprofit organizations, and historic property owners to preserve, protect, and interpret historic sites throughout the United States. Oversees National Register of Historic Places, federal grant and historic rehabilitation tax credit programs, develops standards and guidelines for historic rehabilitation projects, and provides "how to" technical guidance.
National Register of Historic Places - Official list of the nation's historic places worthy of preservation. Part of a national program to coordinate and support public and private efforts to identify, evaluate, and protect America's historic and archeological resources.
National Trust for Historic Preservation - A private, nonprofit membership organization dedicated to saving historic places and revitalizing America's communities.