Whole Hog or None, Excellent Patriotic Civil War Cover

There were a lot of interesting patriotic covers (envelopes) produced during the civil war era, but this my be my favorite I've seen--and quite a concise and effective way of communicating the Union message, I'd say. Note the unusual configuration of the stars on the flag here, too.

5 1/2" x 3 1/16" and in excellent, unused condition.