General view of a female employee analyzing unidentified substances in the Bureau of Chemistry's Pharmacognosy Laboratory. Part of the U.S. Department of Agriculture, the Pharmacognosy Laboratory supervised the manufacture and distribution of crude drugs, specifically those obtained from plants or other natural sources, and investigated methods for preventing waste and improving the utilization of such drugs.

The Bureau of Chemistry was established in 1901 through Congressional appropriations as a successor to the U.S.D.A. Division of Chemistry and significantly built upon the work of its predecessor, which researched the adulteration and misbranding of food and drugs on the American market. The 1906 Food and Drug Act notably increased the Bureau’s regulatory powers and led to the establishment of laboratories for testing the purity and composition of foods and drugs. In 1927, the Bureau of Chemistry effectively disbanded when its powers were reorganized under a new U.S.D.A. body, the Food, Drug, and Insecticide Organization (later the Food and Drug Administration).