The medical advancement highlighted during and after the Battle of Antietam was field hospitals.

The sheer number of casualties necessitated the establishment of organized medical care close to the battlefield. Union and Confederate forces set up makeshift hospitals in local buildings, such as churches and homes, to treat the wounded. This battle underscored the importance of having a systematic approach to medical care in wartime, leading to improvements in triage, sanitation, and the overall organization of battlefield medicine. These developments laid the groundwork for future advancements in military healthcare throughout the Civil War.