During the Civil War, Roswell Sabine Ripley was one of the most significant military leaders in the Charleston theatre of operations and beyond. Rising from the rank of Lieutenant-Colonel in the South Carolina militia, he ended his military career as a Brigadier-General in the service of the Confederate States Army. Current historiography provides limited, if any, analysis or synthesis of the career of this military leader. The purpose of this research is to provide a biographical summary of Ripley's military contributions throughout the war, and in particular his involvement with the defense of Charleston harbor. This research makes use of various primary sources including personal letters and military correspondence from repositories such as the South Carolina Historical Society, the South Caroliniana, and the South Carolina Department of Archives and History. This information coupled with secondary literature allows for a more complete picture of Ripley's personal and military life than does currently exist. The result of this synthesis will illustrate the importance of Ripley's contribution as a military leader in the Civil War and alleviate a missing historiographical component in Civil War history.