This book documents the institutional history of the Chemical Warfare Service (CWS), the U.S. Army organization responsible for chemical warfare, from its origins in 1917 through Amos A. Fries's departure as CWS chief in 1929. It examines the U.S. chemical warfare program as it developed before the nation began sending soldiers to fight in France during World War I; the American Expeditionary Force's experiences with poison gas on the Western Front; the CWS's struggle to continue its chemical weapons program in a hostile political environment after the war; and CWS efforts to improve its public image as well as its reputation in the military in the first half of the 1920s. The book concludes with an assessment of the CWS's successes and failures in the second half of the 1920s. Through the story of the CWS, the book shows how the autonomy of the military-industrial complex can be limited when policymakers are confronted with pervasive, hostile public opinion.