This work is a general historical survey of U.S. Army logistics. It contributes a better understanding of the significance of logistics in the American military experience, and provides an appreciation of some of the Army's logistical problems in its conduct of war from the Revolutionary War through the Korean War. Logistics covers a vast range of subjects. The word logistics came into general military use shortly before World War II, although its substance has been of concern as long as there have been armies. In Army usage it has come to include four principal elements in the support of military operations: (1) supply, including determination of requirements, procurement, and distribution; (2) transportation; (3) evacuation and hospitalization; and (4) service. In short, logistics is the application of time and space factors to war. It is the economics of warfare, and it comprises, in the broadest sense, the three big M's of warfare - materiel, movement, and maintenance. If international politics is the "art of the possible," and war is its instrument, logistics is the art of defining and extending the possible. It provides the substance that physically permits an army to "live and move and have its being."