In 1859 Great Britain and the United States almost went to war over the Northwest boundary when an American farmer shot a British pig. That July, U.S. Army Captain George E. Pickett looked down the gun ports of two British warships from his camp on San Juan Island. He knew he needed help, and the sooner the better. The future Confederate general had been ordered there to protect the rights of U.S. settlers from the might of the British Empire. First...