The State and national governments sent instant relief; the outrages were checked; the Indians were driven up the Minnesota Valley and beaten in several battles; the captive whites were mostly released, and a large number of hostiles engaged in the massacre were taken prisoners. This work was done under the immediate leadership of General H. H. Sibley, first Governor of Minnesota. The captured Indians were tried by court martial, and a great number were condemned to death, but this penalty was commuted by President Lincoln except in the cases of thirty-eight, who were hanged at Mankato, December 26, 1862. [Sidenote: AN INDIAN WAR.] In the meanwhile the Indians under Little Crow, though checked and driven back, were not conquered or discouraged. Their emissaries were active among the tribes of the Missouri, who were aroused almost to the point of war. The execution of the Indians at Mankato exasperated Little Crow to a desperate pitch, and he vowed extermination of the whites. It was clear that an Indian war was at hand, and the government at once prepared for it. Its conduct was placed in the hands of General John Pope, who had been relieved from his command of the Army of the Potomac after the second Bull Run, and was now in command of the Department of the Northwest, with headquarters at Milwaukee. General Pope organized two expeditions, one under General Sibley, to move west from Mankato against the Indians and drive them toward the Missouri, and the other under General Sully, to move from Sioux City up the Missouri and cut off their retreat. The plan was well conceived, but the extreme low water in the Missouri in 1863 prevented General Sully from receiving his supplies in time to carry out his part of the programme. [Sidenote: EXPEDITION OF GENERAL SIBLEY.] Sibley’s expedition left Camp Pope in the Minnesota Valley June 16, 1863, and two days later that of General Sully left Sioux City. Sibley’s route lay up the Minnesota to its source, thence by way of Lake Traverse to the Cheyenne River of North Dakota, and up that stream toward Devil’s Lake, where the Indians were supposed to be. Learning that they had left that region and had gone toward the Missouri, General Sibley changed his march to the southwest, and pursued the retreating enemy with great vigor. He came upon them and fought three battles within a week--Big Mound, July 24; Dead Buffalo Lake, July 26; and Stony Lake, July 28. The Indians were defeated in all three fights, and then crossed the Missouri River just below where Bismarck, N. D., now stands. General Sibley reached that stream on July 29, and here his expedition ended. Two days later his command set out on its homeward march.[69]