The notable command structure during the Battle of Antietam was Decentralized command.

While Union General George McClellan oversaw the Army of the Potomac, he frequently delegated authority to his subordinates, leading to varied execution of his strategies. This decentralization resulted in a lack of cohesion, as some commanders acted independently rather than in concert with McClellan's overall plan. On the Confederate side, General Robert E. Lee also employed a decentralized approach, relying on his generals to make tactical decisions on the battlefield. This command structure had significant implications for the battle's outcome and the effectiveness of the forces involved.