Final answer:
The correct answer is option D) Battle of Gettysburg.
Step-by-step explanation:
The correct answer to the question is D) Battle of Gettysburg. In July of 1863, this intense and critical three-day battle resulted in approximately 51,000 casualties, marking it the battle with the highest number of casualties in the American Civil War. The Battle of Gettysburg began on July 1, as Confederate and Union forces collided unexpectedly.
The conflict reached its peak on the third day with Pickett's Charge, a deadly assault that resulted in significant Confederate losses. The following day, on July 4, Confederate General Robert E. Lee retreated with his army back to Virginia, signifying a major turn in momentum for the Union forces in both the eastern and western theaters of the war.