John Steinbeck wrote "Of Mice and Men" partially based on his experiences working as a hired hand on Californian ranches. He was impressed by the people of rural California, which is where the story takes place.
In the book, the two main characters are George Milton and Lennie Small. They are two displaced migrant ranch workers living during the Great Depression. They go from place to place around California in search of employment opportunities. Steinbeck lived a similar life. He was a bindlestiff, or a homeless person who carries his belongings wrapped in cloth and tied around a stick, in the 1920s. The title of the book comes from a poem by Robert Burns called "To a Mouse."