Wiktionary
boys in blue
n. (boy in blue English)
Usage examples of "boys in blue".
Army Boys in blue carried these into for instance Second Bull Run.
Culliman (herself gowned as Martha Washington) at the climax of a musical tribute certain to raise the spirits and cheer the hearts of our boys in blue?
He saw only too well: the sort of small, tiresome misunderstanding between the department and the boys in blue which could so easily lead to an embarrassing break-down in relations.