 Congress established the "National Capital Park Commission" in 1924 to acquire parkland for the capital in order to preserve forests and natural scenery in and about Washington to prevent pollution of Rock Creek and the Potomac and Anacostia Rivers, and to provide for the comprehensive development of the nation's park system.Two years later, Congress renamed the agency the "National Capital Park and Planning Commission" and gave it the additional responsibility of comprehensive planning for the Washington region.Among its early members was noted Philadelphia architect Clarence C. Zantzinger.