A century of parasite research fills at least 100 boxes at the U.S. Department of Agriculture (USDA) National Agricultural Library (NAL) in Beltsville, Md. These records include photos, drawings, lantern slides, research notes, reports, and correspondence. The documents are part of the U.S. National Animal Parasite Collection Records, which chronicle the parasitology studies of USDA scientists from1886 to 1987.

The parasitology records are one of the more than 200 collections that NAL holds safe, each documenting the history of a USDA program. NAL is a part of USDA's Agricultural Research Service (ARS), USDA's principal intramural scientific research agency.

Such records are not just the dry dust of USDA history, but a continuing resource for researchers. With access to these original materials, scientists can better understand how programs developed and why certain choices were made, explained NAL Special Collections librarian Sara B. Lee.

In addition, writers, historians, sociologists, conservationists, and artists regularly turn to NAL's collections as first-person sources about USDA events, programs and policies.

NAL even preserves the lineage of USDA buildings, especially those located along the National Mall, with a collection of photos and drawings, including an unusual photo showing the original USDA administration building and the unfinished Washington Monument taken from atop the Smithsonian Castle around 1868.

Perhaps the most attractive as well as historically important of NAL's treasures is the USDA Pomological Watercolor Collection, which includes 7,584 paintings, lithographs and line drawings. These technically accurate images were their day's equivalent of photo documentation of fruits, nuts and berries developed by growers or introduced by USDA around the turn of the 20th century.

With today's growing interest in heirloom varieties and others that are no longer commonly grown, the collection is an invaluable storehouse of fruit knowledge and history.

Today, NAL is making its historic collections more accessible. As funds and staffing permit, boxes of records are being more clearly indexed, and documents and images are being scanned. You can find the indexes and scanned materials on the NAL Special Collections web page by going to http://specialcollections.nal.usda.gov, and clicking on "Guide to Collections."

Read more about NAL's USDA history collections in the August 2012 issue of Agricultural Research magazine.