The significant naval battle in U.S. history considered a turning point in the Civil War was the Battle of Gettysburg, which took place from July 1 to July 3, 1863. While it was primarily a land battle, the naval engagements surrounding the war, particularly the use of ironclad ships, shifted naval tactics. Gettysburg marked the turning point in the Eastern Theater as the Confederate Army, led by General Robert E. Lee, faced a crushing defeat against Union forces. This battle significantly halted Lee's invasion of the North and bolstered Union morale, ultimately contributing to the Union victory in the Civil War.