Notes
These are likely part of the U.S. Navy Service Blue uniform, which was the standard-issue winter uniform during World War I. 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. Made out of heavy wool, the waist fit could be adjusted by threading a cord through two eyelets at the back of the waistband. Thirteen buttons secure the front flap, which could be quickly opened by undoing the two corner buttons. This, along with the widely flared pantlegs, made it easy for a sailor to slip out of the heavy pants if they were to fall overboard.