The significance of the Battle of Gettysburg, fought from July 1 to July 3, 1863, lies in its role as a turning point in the American Civil War. It was one of the war's bloodiest battles, resulting in approximately 51,000 casualties. The Union's victory halted the Confederate Army's invasion of the North, bolstering Northern morale and support for the war effort. Additionally, it laid the groundwork for President Abraham Lincoln’s famous Gettysburg Address, which redefined the purpose of the war and the principles of liberty and equality. This battle marked a shift in momentum toward the Union's favor.