In 1844 the USS Yorktown sailed from New York, as part of the U.S. Navy's newly established African Squadron, to interdict slave ships leaving the African coast. Aboard the sloop of war, Master's Mate John C. Lawrence, an educated New Yorker in his early twenties, kept a private journal describing what happened during the extraordinary two-year voyage and his reactions to the events he witnessed. His frank and vivid observations take the reader into...