Ambrose Bierce was an American author, journalist, and satirist who wrote during the late 19th and early 20th centuries. He is best known for his short stories, such as 'An Occurrence at Owl Creek Bridge' and 'The Devil's Dictionary'. He also wrote several novels, including The Monk and the Hangman's Daughter. His work often focused on the dark side of human nature and the horrors of war. He is considered one of the most influential writers of his time.