Final answer:
The claim that the Battle of Gettysburg had the least casualties in the Civil War is false; it had the highest casualties.
Step-by-step explanation:
The statement that the Battle of Gettysburg caused the least amount of casualties during the Civil War is false. The Battle of Gettysburg actually resulted in the highest number of casualties of any battle during the war, with around twenty-three thousand for the Union and approximately twenty-eight thousand for the Confederates. The battle marked the farthest north that the Confederate army advanced and is considered a turning point in the war as it ended Lee's invasion of the North and coincided with the Union victory at Vicksburg.