The nature of the result of the Battle of Gettysburg has been the subject of controversy. Although not seen as overwhelmingly significant at the time, particularly since the war continued for almost two years, in retrospect it has often been cited as the "turning point", usually in combination with the fall of Vicksburg the following day. This is based on the observation that, after Gettysburg, Lee's army conducted no more strategic offensives—his army merely reacted to the initiative of Ulysses S. Grant in 1864 and 1865—and by the speculative viewpoint of the Lost Cause writers that a Confederate victory at Gettysburg might have resulted in the end of the war.