When people think of undersea warfare in the Civil War, most remember the C.S.S. H.L Hunley. Although the Hunley was the first submarine to be used in combat action, as many as 20 other submarines were operational during this time. Many of the sailors on board these vessels lost their lives for the development of submarines. CDR Tory Swanson, USN (Ret.), will discuss submarine use during the Civil War, challenges to submarine research and development, and the innovations that led to some of the naval technology used in our submarine force today.