"Liberty and Union" is not military related, but definitely a patriotic image from the time period. It bears a great resemblance to the vignettes used on early federal currency. I don't think these arched vignettes were actually "bank note" vignettes. They have more the look of book plates.
Here's an example of a citizen soldier recognition certificate, this one was issued by the state of New Jersey in 1867. At the top, you can see two of the vignettes from these panels, with the Battle of the Ironclads at the bottom. Some of these certificates are larger than 24 inches wide. Most of those that survived were framed.