<P> On July 25 , 1866 , Congress created the rank of General of the Army for Grant and then promoted Sherman to lieutenant general . When Grant became president in 1869 , Sherman was appointed Commanding General of the United States Army and promoted to General of the Army . After the death of John A. Rawlins , Sherman also served for one month as interim Secretary of War . His tenure as commanding general was marred by political difficulties , many of which stemmed from disagreements with Secretaries of War Rawlins and William W. Belknap , whom Sherman felt had usurped too much of the Commanding General 's powers , reducing him to a sinecure office . Sherman also clashed with Eastern humanitarians , who were critical of the Army 's killing of Indians and had apparently found an ally in President Grant . To escape these difficulties , from 1874 to 1876 , he moved his headquarters to St. Louis , Missouri , returning to Washington only upon the appointment of Alphonso Taft as Secretary of War and the promise of more authority . </P>
which president was the general in charge of the union army during the civil war
Grant