The line of forts maintained by Colonel Flandrau from the big bend of the Minnesota southward effectively protected Sibley’s left; and it restrained the Winnebagoes from breaking out of their reserve, if they had any such intention, which was very doubtful, although so believed at the time. The right flank of the expedition was not for some time protected. Here were two dangers. Fort Abercrombie had been occupied since spring by Company D of the Fifth Minnesota, under command of Captain John Van der Horck. A newspaper clipping received on August 20 gave him warning of the outbreak of the lower Sioux. He immediately called in his outpost and the few settlers of the Red River valley, proceeded to surround the separate buildings which formed the post with breastworks, and placed three howitzers in the salients. On the last day of the month but one a party of Indians stampeded a herd of stock which had been sent out in anticipation of a treaty with the Red Lake and Pembina Chippeways. On September 3 an Indian force, considerable in number, appeared about the post and maintained a desultory fire for some hours. On the 6th a still larger force made a determined but vain attack, charging with boldness unusual for Indians, first one quarter of the inclosure and then another. The command suffered a loss of two killed and three wounded in the two days’ actions. The Indians were not driven from the neighborhood till September 23, when Captain Emil Burger arrived from below with a relieving force of five hundred men. The mooted question whether these attacks at Abercrombie were made by upper Sioux, lower Sioux, Yanktonnais, or by a mixture of all these, has not been conclusively answered. The capture of this post would have exposed a wide territory to Indian slaughter and depredation.