One reason for the high number of casualties at the Battle of Antietam was ineffective tactics.

Both Union and Confederate commanders often relied on traditional battlefield strategies that were ill-suited for the deadly advancements in weaponry, such as rifled muskets and artillery. Troops were frequently ordered to charge enemy positions without adequate cover or coordination, leading to devastating losses. The clash of outdated tactics with modern weapons created a lethal environment, resulting in one of the bloodiest battles in American history, with approximately 22,000 casualties.