The siege of Charleston during the American Civil War is the longest siege in US history. Using historic images, Richard Blackmon showcases how the siege marked the beginning of a new era in coastal defense that would continue until the Cold War. From July 1863 until February 1865, Union forces maintained offensive operations against the city and its defenses. The importance of the port of Charleston to the Confederate States of America cannot be overstated. Without a large industrial base, the South had to import much of the materiel it needed to wage the Civil War. It was imperative that Confederate military forces keep the port of Charleston open to blockade runners. Conversely, Union forces strained every effort to prevent the Confederates from importing materiel, thereby shortening the war. Federal forces wanted to capture Charleston, considered the starting point of the American Civil War, from the earliest days of the conflict. No concerted, sustained effort materialized until Gen. Quincy A. Gillmore assumed command in June 1863. In September 1862, Gen. P.G.T. Beauregard assumed command of Confederate forces defending Charleston. Both commanders established the nature of the siege by embracing technological advances and innovations in military warfare.  Richard Blackmon is a historian and university instructor. His previous publications include Dark and Bloody Ground: The American Revolution along the Southern Frontier, The Creek War: 1813-1814, and The Battle of Cowpens: Turning Point in the American Revolution . Current projects include the 1864 Savannah Campaign and the American Civil War on the lower Atlantic coast.