American Civil War era The rank of lieutenant general remained inactive from the end of the Revolutionary War until the mid-19th century. During the Mexican–American War, President Polk asked Congress to authorize the creation of a lieutenant-general. However, it soon became clear that Polk intended to give this rank to Senator Thomas Hart Benton and place him in charge of the entire war effort—a move that would place Benton, a Democrat and Polk ally, above the two Whig generals who had been conducting the war (Zachary Taylor and Winfield Scott). As a result, Congress refused to authorize this rank. The rank of lieutenant general was finally created in 1855, when Winfield Scott received a brevet promotion to this rank. On 13 March 1861, General Order No. 6 said that the position of Major General Commanding the Army was entitled to wear three stars. In 1864, Ulysses S. Grant was appointed lieutenant general and took command of the Union forces. He used the three-star insignia formerly assigned to the position of Major General Commanding the Army. The Confederate States Army used the rank of lieutenant general for its corps commanders prior to the U.S. Army's adoption of the term. The two ranks were not synonymous. Unlike the Union Army, the Confederate States Army promoted numerous officers to the ranks of Lieutenant General and General (18 and 7, respectively). In the 19th century, the rank of a U.S. general was also shown by the arrangement of buttons on the coat. This was a feature of the general dress uniform until the Army abandoned blue uniforms during World War I. On 25 July 1866, the U.S. Congress established the rank of "General of the Army of the United States" for Ulysses S. Grant. When appointed General of the Army, Grant wore the rank insignia of four stars and coat buttons arranged in three groups of four. Unlike the 1944 rank with a similar title, the 1866 rank of General of the Army was a four-star rank, and as opposed to the current pool of four-star generals, only one officer could hold the 1866–1888 rank of General of the Army at any time. After Grant retired to become President of the United States, he was succeeded as General of the Army by William T. Sherman, effective 4 March 1869. In 1872, Sherman ordered the insignia changed to two stars with the arms of the