This book provides a holistic analysis of four Plains Indian War Campaigns. Lieutenant General (LTG) Philip Sheridan conducted all four campaigns. This analysis illustrates several enduring principles of both operational art and counterinsurgency (COIN) operations. The purpose of the book is to explain the initial failure of LTG Sheridan's 1876 Centennial Campaign against the Sioux and Cheyenne Indians. Additionally, this explanation relates the significance of LTG Sheridan's planning to contemporary COIN campaign planning. The overall methodology is the incorporation of four case studies to test the theory of sanctuary control and elimination of resources to defeat insurgencies. The four case studies include: the 1868-1869 Cheyenne War, the 1874-1875 Red River War, the 1876 Centennial Campaign, and the 1876-1877 Sioux Campaign. This book contains three key findings. The first key finding is that the failure at the Little Big Horn was LTG Sheridan's fault not LTC Custer's, and this directly relates to the second finding. The second key finding is the importance of operational art in designing a campaign plan to link tactical actions to strategic objectives. The third finding is the efficacy of some of the current COIN tenets.