This thematic framework is a revision of "History and Prehistory in the National Park System and the National Historic Landmarks Program," 1982. Thematic classification of the United States' historic resources is much older, however. It was urged in 1929 by the Committee on the Study of Educational Problems in National Parks, the predecessor of the National Park System Advisory Board. The first them outline was adopted by the Board in 1936. It was well understood by the scholarly community represented on these bodies, that classification of resources is intrinsic to an understanding of a body of knowledge about these resources and is fundamental to the comparative analysis necessary in making judgments of relative significance.
The outline is used to show the extent to which units and cultural resources of the National Park System, affiliated areas, and National Historic Landmarks reflect the Nation's past. Parks and Landmarks are assigned to all themes, subthemes, and facets in which they are found to be nationally significant. By this process the comprehensiveness of the Survey of National Historic Landmarks and the representativeness of the National Park System can be gauged and planning for further study guided.
The framework guides those involved in historical survey at national, regional, state, park, or local levels, since the them structure is a comprehensive outline of United States history, prehistory, and cultural endeavors, rather than a structure biased by existing or estimated numbers and concentrations of Landmarks and other historic resources.
The purpose is to cover all areas of United States history without excessive detail and minutiae. To that end, the 1982 framework has been changed in some important ways. Some theme titles like "VII. America at Work," "VIII. The Contemplative Society", and "IX. Society and Social Conscience" were judged not to be adequately meaningful and were discarded. In their place, the subject titles previously subordinated to them, such as architecture, engineering, and conservation, were raised to the theme level. This brings those and other major fields of endeavor more into balance with the more traditional themes of political and military history and westward expansion. The Major American Wars and Political and Military Affairs themes were not necessarily exclusive of each other and are easily merged into one larger, essentially chronological theme. This covers, in essence, American governmental history along with the Nation's major military conflicts. While the number of themes has therefore been increased from 9 to 34, the latter number is roughly equal to the previous number of subthemes and does not represent new areas for study. By raising previous subthemes to theme level, the lowest echelon, the subfacets, are eliminated leaving only three levels to consider --- theme, subtheme, and facet. An example of the three levels is as follows:
XIII. SCIENCE (Theme level)
To cover more thoroughly the varies aspects of United States history, the subtheme Transportation and Communication, for example, has been separated into its two individual components while the Science and Invention subtheme was newly arranged so that Science becomes a separate entity and Invention was combined with the Engineering subtheme to form a new expanded theme under the new heading of Technology. Other subthemes have been added and facets raised to the subtheme level so that more important components of certain historical themes receive greater recognition. The facet levels have been refined, condensed, or enlarged where needed, so that more precise and significant coverage of all aspects of the subthemes is provided.
There is a significant change in Theme I, previously entitled, The Original Inhabitants. This outline, traditionally understood to cover archeological sites, has been expanded to reflect greater detail and currency in archeology and to provide a broader range for ethnohistory. Revised assignments of National Park System Unites and National Historic Landmarks to categories within this theme is absent from the outline. These are being prepared and are expected to appear in a supplement which will be incorporated into a later edition of this publication. It was not thought worthwhile to reproduce the assignments of the previous (1982) outline in this theme.
In the previous (1982) edition, many subthemes specifically excluded aspects covered in other subthemes. Under this scheme, western mining in the 19th century was excluded from Commerce and Industry, even though no one doubts that resources of national significance relate to both areas. These exclusions have been eliminated.
The dates given for various themes or subthemes will bracket specific times, as is the case for wars, or with other classifications that are accepted by the professional community, such as architectural periods. There are, however, precursors and later phenomena to be found outside of any given time frame. Therefore, the dates given in this document are not meant to be rigidly imposed, but to be used as general guides to placement.
With the above changes, it is hoped that the users of this revised theme structure will find that it offers them greater flexibility, clarity, and direction in classification and survey, thus, making it more convenient to use. The thematic outline is an evolving framework; it will change s our understanding of history and prehistory changes and National Historic Landmarks are designated and de-designated. Readers are invited to comment on this publication so that it might receive continuous review for successive revision.
Edwin C. Bearss