Oregon, Bozeman and Santa Fe Trails. Tasked with guarding a vast territory with limited forces, Sherman grew weary of the multitude of requests for military protection addressed to him. On July 25, 1866, the U.S. Congress created the new rank of General of the Army for Grant, while also promoting Sherman to Grant's previous rank of lieutenant general. Indian Wars There was little large-scale military action against the Indians during the first three years of Sherman's tenure as divisional commander, as Sherman allowed negotiations between the U.S. government and Indian leaders to proceed, while he built up his troops and awaited completion of the Union Pacific and Kansas Pacific Railroads. During this time he 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 those treaties because in both cases he was called away to Washington during the negotiations. In one instance, he was summoned to testify as a witness in Andrew Johnson's impeachment trial. He testified in the trial on April 11 and 13, 1868. He 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 failed in 1868, Sherman authorized his subordinate in Missouri, Major General Philip Sheridan, to lead the winter campaign of 1868–69, of which the Battle of Washita River was part. Sheridan used hard-war tactics similar to those he and Sherman had employed in the Civil War. In 1871, Sherman ordered that the leaders of the Warren Wagon Train Raid, an attack by a Kiowa and Comanche war party from which Sherman himself had narrowly escaped, be tried for murder in Jacksboro, Texas. The resulting trial of Satanta and Big Tree marked the first occasion in which Native American chiefs were tried by a civilian court in the United States. Sherman regarded the expansion of the railroad system "as the most important element now in progress to facilitate the military interests of our Frontier". One of the main concerns of his postbellum service was, therefore, to protect the construction and operation of the railroads from hostile Indians. Sherman's views on Indian matters were often strongly expressed. Following the 1866 Fetterman Massacre, in which 81 U.S. soldiers were ambushed and