Of Mice and Men
Warning: Wikipedia contains spoilers
Of Mice and Men is a novel by John Steinbeck which tells the story of George and Lennie, two of many men displaced by the Great Depression. Lennie is a large man with the mind of a child, and George is a small man with a quick wit. When Lennie accidentally kills the wife of their boss's son, George kills him to protect him from the wrath of the men who are chasing him.
The novel was made into two films:American school libraries or curricula in 1993 and 1994 for "profane language, moral statement, treatment of the retarded, and the violent ending".