Notes
This is likely a U.S. Navy Service Undress Blue jumper, which was part of the standard-issue winter uniform used during World War II. It was also commonly called the "Crackerjack" uniform, which arose from its similarity to the uniform worn by the mascot of the Cracker Jack snack brand, Sailor Jack. These jumpers were made out of a heavy navy blue melton wool, featuring a wide collared, pullover design that was intended to allow a sailor to quickly remove the shirt if he were to go overboard.