After he captured the Democratic presidential nomination, McClellan repudiated the peace plank of the Democratic platform and instead vowed to continue the war effort and to do a better job with this than the incumbent Lincoln Administration was doing. McClellan emphasized the fact that he previously led the Union military effort in the American Civil War and that he was and remains committed to "the restoration of the Union in all its integrity" due to his belief that the massive sacrifices that the Union endured during this war should not be in vain. Incumbent U.S. President Abraham Lincoln worried about his reelection chances and was afraid that if McClellan won the election, the Copperheads (the Peace faction of the Democratic Party) would successfully pressure McClellan to recant his campaign promise to continue the war. Thus, Lincoln made his Cabinet secretly promise to cooperate with McClellan if he won the election to win the war by the time that McClellan will be inaugurated. Fortunately for Lincoln, the tide of the war effort began to turn in the Union's favor in the autumn of 1864 as a result of Union General William Tecumseh Sherman's capture of Atlanta on September 2 as well as Sherman's subsequent military successes. These successes increased Lincoln's popularity and reduced McClellan's chances of defeating Lincoln in November 1864.