Al Capone Does My Shirts, by Gennifer Choldenko, 2004

Al Capone really does launder 12-year old Moose Flanagan's shirts, ever since his family moved to Alcatraz, where rent's cheap during the Great Depression and his dad is able to get two jobs at the prison. They need the money to send Natalie, Moose's (younger? older?) sister to a special school for children with mental disabilities. Only problem is, the school has an age cutoff for admission, and Natalie's been celebrating her tenth birthday for the past six years straight. Thoughtful, funny middle grade historical realism that successfully mixes autism, baseball, and the mafia, with an enviably original and well-researched setting. Recommended.