In the summer of 1866, Colonel Henry B. Carrington set out from Fort Laramie to establish a series of forts along the Bozeman Trail with the goal of protecting migrants moving along the trail. The Bozeman Trail ran through the Powder River country, which included the traditional hunting grounds of Lakota, Cheyenne, and Arapaho peoples. Carrington had about 1,000 people in his column, of which about 700 were soldiers and 300 were civilians, likely soldiers' families and migrants.

The ongoing hostilities, which included the notorious Fetterman's Massacre, ultimately convinced American officials to head back to the negotiating table with the Native Americans, and as a result, Red Cloud has often been labeled the only Indian chief to win a war against the Americans. After that, however, Red Cloud continued to lead his people to reservations first near the Black Hills and later westward after the Battle of the Little Bighorn. Though he was respected as a war chief, it was his political functions as a spokesman of the Oglala that truly allowed Red Cloud to leave his mark over the last several decades of his life. Whereas Sitting Bull and Crazy Horse suffered premature deaths, Red Cloud outlived the other important leaders of the Sioux until dying in 1909 at 87 years old. Near the end of his life, he reportedly said, "They made us many promises, more than I can remember. But they kept but one — they promised to take our land...and they took it."

Red Cloud's War: The History and Legacy of the Only 19th Century War Won by Native Americans against the United States analyzes the seminal moments that brought about the war, the war's most famous battles, and the aftermath.