The outbreak of the Civil War found Ulysses S. Grant working as a clerk in his brother's leather store in Illinois. Although he had been graduated from West Point and had served with distinction in the Mexican War, Grant had no intention of making his career in the military. He resigned from the Army as a captain in 1854 and held a series of odd jobs, including selling firewood in the streets of St. Louis. Upon Lincoln's call for volunteers, Grant applied in vain to the federal government for a commission. However, he was appointed a colonel of the 21st Illinois volunteers in June of 1861. When Grant's forces attacked Fort Donelson and the Confederate commander tried to negotiate, Grant replied that "no terms except an unconditional and immediate surrender can be accepted." The subsequent capitulation earned him the nickname "Unconditional Surrender Grant" (a play on his initials) and prompted Lincoln to name him a major-general of volunteers. Victories at Vicksburg and Chattanooga confirmed his reputation as a winner, and on March 17, 1864. Lincoln gave him formal control of all northern armies. Union troops suffered severe losses as Grant forced the Confederate army to retreat towards Richmond. Answering criticism of his tactics, Grant declared after the bloody fighting at Spotsylvania Court House: "I propose to fight it out on this line if it takes all summer." On April 9, 1865, after the capture of Petersburg and Richmond, Robert E. Lee surrendered to Grant at the Appomattox Court House. In 1869, Ulysses S. Grant became the 18th president of the United States.