The general responsible for the Union's defense at Fort Sumter was Robert Anderson.

General Robert Anderson was the commanding officer responsible for the Union's defense at Fort Sumter during its bombardment in April 1861. A career military officer, Anderson had previously served in various posts before taking command of the fort. His leadership became crucial as Confederate forces initiated the attack, marking the beginning of the Civil War. Despite being outnumbered and facing significant artillery fire, Anderson and his garrison held out for 34 hours before surrendering. His decision to defend the fort became symbolic of the Union's commitment to preserving the nation, and his actions were recognized for their courage and determination.