Harney returned to Fort Laramie with 70 prisoners, most of them women and children. On October 25 the three warriors sought by the expedition surrendered, were held for a year at Fort Leavenworth, and were released. Harney ordered the tribes to send representatives to a treaty council at Fort Pierre in March 1856, where a treaty was signed on terms dictated by the War Department. Twiss tried to undermine the treaty, and Harney had him removed from office, although he did not have the authority to do so. Commissioner of Indian Affairs George W. Manypenny successfully lobbied the Senate to reject the treaty, and Twiss was reinstated. Harney's actions against the Lakota restrained them for nearly ten years. The US was soon involved in the American Civil War, and did not have resources to fight on the Great Plains.