been knocked off their horses by an artillery round. Across the wide Missouri After the Sioux had departed, Sibley marched his men unmolested for 18 miles and camped on Apple Creek, about 10 miles southeast of present-day Bismarck, North Dakota. He had anticipated meeting Sully, who was supposed to be proceeding up the Missouri River by steamboat, near there but there was no sign of him. The next morning, July 29, Sibley sent two howitzers and his mounted Rangers forward about 12 miles to attempt to prevent the Sioux from crossing the Missouri River. He was too late; most had crossed the preceding day, but, in their hasty flight had been forced to abandon many of their belongings. Some of the warriors were still on the eastern side of the Missouri and Sibley shelled them, causing them to swim across the river to the safer western side where they continued to fire at long distance on Sibley's men. Two of Sibley's men, separated from the main body of soldiers were killed. Sibley camped near the river and the next three nights was subjected to constant, small-scale attacks by the Sioux who burned the prairie, fired into the army's tents, and stampeded some livestock. With Sully, supplies, and reinforcements nowhere to be found, Sibley decided on July 31 to abandon the operation and march back to Minnesota. His horses and men were worn down. Sibley proclaimed his expedition a success as he had pushed the Sioux westward across the Missouri River, far from the settlements in Minnesota and eastern Dakota territory. He claimed to have killed and wounded 150 Indians in the three battles at a loss to his own forces of six men killed. The Santee chief, Standing Buffalo, however, claimed that only 13 Indians had been killed. It is impossible to reconcile the different estimates of Sioux casualties, as it is to determine with precision how many Indian warriors were actually engaged in the battles. The Sioux took their revenge on August 3, three days after Sibley had left the banks of the Missouri to return to Minnesota. They attacked a river raft and killed 22 civilians. Nor did raids into Minnesota cease as sixteen whites are known to have been killed by Sioux later in 1863. Later that summer, Sully, tardy in joining forces with Sibley, would meet the Sioux in the Battle of Whitestone Hill. Federal units