Recent scholarly work on the history and significance of logistics suggests logistics is 90% of the business of war. Logistics enables the deployment of armies to war and their subsequent movement and sustainment during war. As such, transportation - strategic, operational, and tactical - is the most significant of the Combat Service Support (CSS) Functions. This monograph explores theory, history, and doctrine in order to determine if past expeditions into Afghanistan offer logistics lessons to 21st Century U.S. Army expeditions. The monograph also proposes how the U.S. Army can best deploy and supply its expeditionary forces in the future.