Final answer:
The Battle of Gettysburg was the 3-day battle that signaled a major turning point in the Civil War, following which General Lee was unable to launch further invasions into the North. With significant casualties on both sides, this battle, coupled with the Union's victory at Vicksburg, shifted the war's momentum in favor of the Union.
Step-by-step explanation:
The Turning Point of the Civil War: The Battle of Gettysburg
The 3-day battle that marked a major turning point in the Civil War was the Battle of Gettysburg, which occurred from July 1 to July 3, 1863. This pivotal clash ended with a decisive Union victory, thwarting General Robert E. Lee's Confederate incursion into the North. On the battle's final day, Pickett's Charge resulted in heavy Confederate losses, and Lee's forces were compelled to retreat back to Virginia. The Union's success at Gettysburg, along with the capture of Vicksburg by Union General Ulysses S. Grant, significantly shifted the war's momentum in favor of the Union forces in both the eastern and western theaters. The Battle of Gettysburg represented the last time Lee would conduct a major offensive into Northern territory, marking the beginning of more defensive tactics by the Confederate Army. Despite its significance, the battle also resulted in staggering casualties, with the Union forces incurring around 23,000 losses, while Confederate losses were approximately 28,000. The United States would continue to see various battles throughout the war, but the strategic advantage gained during this period, particularly with the twin victories at Gettysburg and Vicksburg, critically undermined the Confederacy's ability to sustain its fight.