Abstract Collection contains memoranda, correspondence, reports, handbooks, publications, articles, bibliographies, conference materials, photographs, catalogs, notes, and architectural drawings collected by David G. Henderson in the course of his career as an architect for the National Park Service. The material dates from 1926-88 (bulk: 1963-82). The collection deals with issues of historic preservation. It includes internal National Park Service memoranda, guidelines, procedures, and policies, as...