There was little large-scale military action against the Indians during the first three years of Sherman's tenure as divisional commander, as Sherman was willing to let the process of negotiations play out in order to buy time to procure more troops and allow the completion of the Union Pacific and Kansas Pacific Railroads. During this time Sherman was a member of the Indian Peace Commission. Though the commission was responsible for the negotiation of the Medicine Lodge Treaty and the Treaty of Fort Laramie, Sherman did not play a significant role in the drafting of the treaties because in both cases he was called away to Washington during the negotiations. In one instance, he was called to testify in the impeachment trial of Andrew Johnson. However, Sherman was successful in negotiating other treaties, such as the removal of Navajos from the Bosque Redondo to traditional lands in Western New Mexico. When the Medicine Lodge Treaty was broken in 1868, Sherman authorized his subordinate in Missouri, Philip Sheridan, to conduct the winter campaign of 1868–69, of which the Battle of Washita River was a part. Sheridan used hard-war tactics similar to those he and Sherman had employed in the Civil War. Sherman was also involved with the trial of Satanta and Big Tree: he ordered that the two chiefs should be tried as common criminals for their role in the Warren Wagon Train Raid, a raid in which Sherman himself came dangerously close to being killed.