This historical collection by the USDA is a great source for those interested in researching the history of dietary guidelines in the US, or anyone curious to trace what we have collectively thought of as healthy foods over the last 100 years. Using its collection of historical nutrition education materials, the National Agricultural Library (NAL) has digitized and organized more than 1,200 items to create the Historical Dietary Guidance Digital Collection, which now includes posters, recipes, transcripts of radio broadcasts, and some current nutrition education materials. The collection can be searched or browsed by subject. Included in the collection is a transcript of the USDA "Housekeepers Chat," a radio show dated September 3, 1931, on how to examine the labels of canned mushrooms, which is an interesting read from our 21st-century perspective. This 20th-century lesson concentrates on how to determine the quality of the canned mushrooms and their place of origin. The Food Guide Pyramid was released in the 1990s; to find earlier versions, search on guidelines or dietary guidelines to retrieve historical advice going back to the 1960s, often published in "Food & Nutrition," a newsletter published by USDA beginning in 1971. On many materials, NAL provides the helpful reminder: "These documents are historical; please do not assume this content reflects current scientific knowledge, policies, or practices."