they weren’t so much the box car children, but children making box cars and box trucks and box trains, etc.
with old snack boxes, stickers, tape, tickets, crayons, scissors (though tearing works as well sometimes), paper fasteners pencils and glue, they made more transportation!
some knew they wanted “smoke stuff” to come out of that “pipe thing that is at the back.”
some even had built in windows. : )