The USDA Chestnut Tree Research Records documents chestnut tree seed distribution and growth across the United States, England, and Canada in the early-to-mid-twentieth century. The program served to reintroduce and monitor the progress of various species of chestnut trees following the introduction of Cryphonectria parasitica, or chestnut blight, from East Asia to North America and Europe in the early 1900s. | The USDA Chestnut Tree Research Records consists of a series of notecards documenting chestnut seed distribution and tree growth across the United States, England, and Canada in the early-to-mid twentieth century. The information on each notecard varies, and includes but is not limited to the geographic location of where chestnut trees were planted or seeds distributed; the species of the chestnut tree(s); the name of the person, organization, agency, and or address to which seeds were distributed or planted; dates seeds were distributed or trees observed; notes about the conditions or specific locations of the trees and whether they contain blight; as well as a Plant Inventory (PI) number. Although the collection is primarily composed of informational notecards, some items include hand drawn maps, photos, letters, newspaper articles, and other supporting documentation. | The Plant Inventory (PI) numbers that appear on many of the notecards originate from the U.S. Department of Agriculture's Bureau of Plant Industry Inventory of Seeds and Plants Imported by the Office of Foreign Seed and Plant Introduction, published in the late nineteenth century and throughout the twentieth century. In some cases, the PI number can be cross-referenced with PI numbers appearing on other cards in the collection, which can help identify the specific species and geographic origin of the trees or seedlings distributed.