As was the custom in the 19th century, foreign nations sent observers to other nations' wars, where these observers could learn tactics, see the latest weaponry, and report back to their own country. General George B. McClellan was an observer of the Crimean War and saw the Siege of Sevestapol, which heavily influenced his tactics during the Civil War. The Confederacy had a few of them, most notably the British observer Arthur Fremantle, who witnessed...