Pursuant to the plan, Brigadier-General Henry B. Carrington, Colonel of the Eighteenth Regular Infantry, was ordered with the second battalion of his regiment, about to become the Twenty-seventh Regular Infantry, to establish, organize and take command of what was known as the Mountain District. The Mountain District at that time had but one post in it, Fort Reno, one hundred and sixty miles from Fort Laramie. Carrington was directed to march to Fort Reno, move it forty miles westward, garrison it, and then, with the balance of his command, establish another post on the Bozeman trail, between the Big Horn Mountains and the Powder River, so as to command that valley much frequented by Indians; and, lastly, to establish two other posts, one on the Big Horn, the other on the Yellowstone, for the further protection of the trail. General Carrington was a graduate of Yale College. He had been a teacher, an engineer and scientist, a lawyer and man of affairs, a student of military matters as well as Adjutant-General of Ohio for several years prior to the outbreak of the Civil War. At the beginning of that struggle he promptly moved one battery and several regiments of Ohio Militia into West Virginia to take part in the Battle of Phillipi before the State Volunteers could be mustered into the United States service. Without his solicitation, on May 14th, 1861, he had been appointed Colonel of the Eighteenth United States Infantry, promoted Brigadier-General November 29th, 1863, and had rendered valuable and important services during the war. He was a high-minded Christian gentleman, a soldier of large experience and proven courage, an administrator of vigor and capacity, and, as his subsequent career has shown, a man of fine literary talents.[5] No better choice could have been made for the expedition. After many delays, due principally to difficulties in securing transportation, a little army of seven hundred men, accompanied by four pieces of artillery, two hundred and twenty-six wagons, and a few ambulances containing the wives and children of several of the officers, set forth from old Fort Kearney, Nebraska, on the 19th of May, 1866. About two hundred of the men were veterans, the rest raw recruits. They were armed with old-fashioned Springfield, muzzle-loading muskets, save a few who had the new Spencer breech-loading carbine, a weapon of rather short trajectory, but a great improvement on the old army musket from the rapidity of fire which it permitted. A portion of the command was mounted from the discarded horses of a cavalry regiment going east to be mustered out. They were not trained horsemen, however, and at first were rather indifferent mounted infantrymen.