Why are they called navy beans?
Navy beans are small and oval and cook relatively quickly (which, as Aliza Green notes in The Bean Bible, has made them popular with commercial baked bean manufacturers).
Known as Boston beans, the white coco, pea beans or alubias chicas, navy beans are perfect for dishes that don't need the full bean shape to shine: purées, soups, stews and baked beans.
Navy beans get their name because of their role as a staple food for the U.S. Navy. The beans were first mixed with molasses and canned in 1875; Heinz introduced canned beans with tomato sauce in 1895.