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NATIONAL REGISTER INFORMATION SYSTEM

Overview and Status

The National Register of Historic Places has begun the task of digitizing the National Register documentation on listed properties and is looking for states, federal agencies, and tribes to partner with in completing this exciting endeavor. If you are interested please contact the database manager . Beginning by commissioning a study by the Cornell Institute for Digital Collections of our own collection, we next scanned the text of multiple covers because it seemed most immediately useful to others, and then, because outside funding was available, all properties owned by the General Services Administration, a federal agency. Both of these subsets are online. We recently finished scanning nominations in Kentucky, all NPS-owned nominations, all National Historic Landmarks, and are in the process of scanning the text of Illinois nominations. We are planning to put these subsets online in revised web software. Generally the digitizing process includes making images of all of the nomination text, all photographs, selected USGS maps and linking them to a database. We are not currently 'based-funded' for this activity, have a long way to go, and hope to be able to benefit from the many excellent efforts of our partners. A gateway to those efforts is available at SHPO inventories .

Approach

Our approach has been to select logical subsets of National Register documentation as funds become available, to freely share our efforts with others, and incorporate the products of others whenever possible. We have not used OCR, or optical character recognition, on the nomination text opting for capturing as faithful a copy of the actual nomination as is feasible. We have used the guidelines set by the National Archives and Records Administration. We strive to balance the requirements for preservation and access by scanning at sufficient resolution to have an 'archival' copy while at the same time providing photographics derivatives of this information for information sharing in the commonly used Adobe Acrobat PDF, or portable document format, for quicker display over the web. The publicly available information includes a redacted version of any restricted information and exludes photographs of restricted information. We plan to continue to provide access to this information via a Web enabled database with links to two PDF files for each property, one for text and one for photographs. We are undertaking a major revision of our web database to allow for more robust searching and expanded search capability. While the Web technology will grow in sophistication and power as we move forward with new technologies, we also encourage others to download PDF files for incorporation into their own information systems for their own purposes. You may contact us about obtaining a specialized subset. We scan maps only in those cases where there is not an adequate verbal boundary description since Internet mapping has evolved to the point where feeding proper coordinates from a database can reasonably plot a property on a topographic map. We keep the pointers to a scanned nomination as only one of a number of other links to resources managed by the National Register Information System, such as National Register Travel Itineraries. Backups of this information are stored at a secure offsite location. The raw database files about National Register properties is available to anybody for downloading.

Methodology

We prepare all nominations for sending out in batches in-house to our scanning contractor. Nominations are bar coded, checked out when they leave and checked in when they return. We update our database for missing properties and update a flag when scanning is completed. Prep work includes putting the files in the right order and clipping what is to be scanned. We xerox pages that are too fragile for scanning. In cases where there is restricted information we make a copy of the nomination text and blacken out all sensitive information. Items like correspondence are not scanned. Text is delivered to us on CD ROM by a scanning contractor as both individual pages and in multi-page uncompressed TIFFS so, as mistakes are uncovered, or we receive additional documentation, we can add a page and remake the multi-page TIFF. Photographs are also delivered as uncompressed TIFFS, however there is no multi-page TIFF made due to the large size of these files. All photographs and all documentation describing photographs is scanned on the assumption that, while expensive, we are only going to get one crack at it. The photographs are manipulated in graphics software to maximize their information content. Captions are scanned without cropping and rotated if askew. Sketch maps and topo maps are scanned as necessary after first reducing to an 8 1/2" by 11" format and xeroxing in grayscale. Topographic maps are only scanned when there is no adequate legal boundary description since we feed UTM coordinates for display on the Topozone web site. The master copy is always a TIFF, although photographs are converted to JPEG images for speedier delivery over the Web. We make the JPEG derivatives for photos and all the Acrobat files in-house to save money. Images are currently stored on a dual processor server with a dozen 36 gigabyte drives configured with RAID 5 for redundancy. Offsite storage is kept on 100 gigabyte Ultrium tape drives. We scan at 400 dpi bitonal uncompressed TIFF for text, 300 dpi grayscale uncompressed TIFF for photos, and 300 dpi grayscale uncompressed TIFF for maps (only as necessary). Text is served through a single Adobe Acrobat file using the eight digit National Register number with PDF as the extension on the file name (e.g. 66000005.PDF). Photographs are stored similarly except they are stored in a photo directory. Maps scanned in grayscale are stored behind the photographs in the PDF photographic file. Thumbnails are available for previewing in Acrobat and the 'fast web' option is enabled for speedier delivery. We make the original TIFFs available to partners on electronic media.