Many great books stem from real-life stories, but we often ignore to what degree. Few people know that, before Moby-Dick, there was a real whale that sank a ship and left its crew adrift for 90 days. Or that it was the four Alcott sisters living in Massachusetts who inspired the four March sisters from Little Women. The ten novels in this article have collectively sold hundreds of millions of copies; here are the true stories behind 10 of the most famous books ever written.