But while the severe lesson of Ash Hollow, the frank counsel of General Harney, and the presence of a military force at Fort Randall, kept the tribes in comparative peace, the wrongs from which they suffered continually increased, and their temper grew constantly worse. The discovery of gold in Montana brought a multitude of emigrants to and through this country, with the consequent destruction of game and threats of roads and railroads and loss of lands. Events were fast developing into a crisis, when the outbreak of the Civil War in the United States gave the tribes their desired opportunity. The frontier garrisons were depleted in order that the regular troops might be sent south. New levies made up of the able-bodied citizens went away to the war. The Indian was quick to see how this movement weakened the frontier settlements. He was made to believe, by gross exaggeration, that the situation of the Great Father in Washington was a desperate one, that his capital was about to be taken and his power destroyed. It has been asserted that the Confederates had emissaries among the Indians, but there is no proof of any direct intrigue of this character. Indirectly, however, they exercised a powerful influence upon them. The people of the British possessions, like those of the mother country, sympathized ardently with the South, and this sympathy found effective expression in the intercourse of the British half-breeds north of the boundary with the Indians south. These half-breeds knew the border tribes perfectly, and had greater influence with them than the whites, who were strangers to their customs and the authors of their many wrongs. Selfish motives of trade combined with national prejudice to stir up strife against the Americans and to provide means for making that strife effective. The half-breeds circulated freely south of the border, and the tracks of their carts could be seen everywhere from the Red River of the North to the Missouri River. They brought powder and balls, guns, rum, and regular merchandise of trade, and their influence at this particular time was decisive. Their territory, moreover, offered a sure asylum from punishment for any outrages which the Indians might commit.[68] [Sidenote: THE MINNESOTA MASSACRE.] Trouble first broke out in 1862 among the Minnesota Indians, where the evil conditions from which the tribes had been suffering had reached an acute stage. Under the leadership of a noted Sioux chief, Little Crow, the Indians in the valley of the Minnesota River above Mankato attacked the settlement of New Ulm and others in that vicinity, on the 18th of August, murdering and taking captive the inhabitants, destroying property, and spreading consternation in every direction. In the course of three days nearly a thousand persons were killed and two million dollars’ worth of property destroyed.