Answer:
Battle of Shiloh
Step-by-step explanation:
The Battle of Shiloh took place in April 6-7, 1862 in Southwestern Tennessee. This battle was extremely costly. It led to the defeat of the Confederate Army, and a Northern victory. Nevertheless, the war led to more deaths on the Union side than on the Confederate side, as well as a loss in reputation on the part of Ulysses S. Grant. At the time, it was also the most costly battle, as well as the battle with the highest number of casualties.