One of the tactics used by the Confederates during the Battle of Antietam was establishing defensive positions.

General Robert E. Lee's forces utilized the terrain to their advantage, digging in and fortifying their lines along critical points, such as the Sunken Road and the High Water Mark. This defensive strategy aimed to withstand the Union assaults, allowing Confederate troops to inflict significant casualties while minimizing their own losses. By holding strong defensive positions, the Confederates sought to repel the Union advances and create a challenging environment for the attacking forces, ultimately prolonging the battle and their defense of Southern territory.