The summer of 1865 marked the transition from the Civil War to Indian war on the western plains. With the rest of the country's attention still focused on the East, the U.S. Army began an often forgotten campaign against the Sioux, Cheyenne, and Arapaho. Led by Gen. Patrick Connor, the Powder River Indian Expedition into Wyoming sought to punish tribes for raids earlier that year. Patrick Connor's War describes the troops' movement into hostile territory while struggling with bad weather, supply shortages, and communication problems.