John Gregory Bourke 
On the Border with Crook General George Crook, the American Indian Wars and Life on the American Frontier [EPUB ebook] 

"Among the ten best Western books of all time. It has that rare combination, a personal reminiscence covering important events, and a thoroughly scholarly and reliable treatment." – Westerners Brand Book. For fifteen years John G. Bourke served under General George Crook as they fought side by side on the frontiers of the United States from Mexico to the Canadian border. Crook and his troops clashed against some of the most formidable opponents of the nineteenth century during the Great Sioux War and the Apache Wars, including Sitting Bull, Crazy Horse and Geronimo. This fascinating account of these times brings to life the frontier of the Old West, with vivid descriptions, humorous anecdotes and deadly encounters. On the Border with Crook is essential reading for anyone interested in not only Crook’s military campaigns of the American Indian wars but also anyone wishing to find out how settlers and communities survived and prospered through adversity. (Goodreads)