The Civil War is one of the most studied and written about episodes in the history of the United States, and remains the subject of cultural and historiographical debate. Of particular interest is the persisting myth of the Lost Cause of the Confederacy. The American Civil War was among the earliest to employ industrial warfare. Railroads, the telegraph, steamships, the ironclad warship, and mass-produced weapons were employed extensively. In total the war left between 620,000 and 750,000 soldiers dead, along with an undetermined number of civilian casualties. President Lincoln was assassinated just five days after Lee's surrender. The Civil War remains the deadliest military conflict in American history, and accounted for more American military deaths than all other wars combined until the Vietnam War. The mobilization of civilian factories, mines, shipyards, banks, transportation, and food supplies all foreshadowed the impact of industrialization in World War I, World War II, and subsequent conflicts.