Your post jogged my memory and I had to dig through a different part of my collection. For the banquet of the 1987 plate printers convention, the U.S. Banknote Company distributed a folder of six "compliments" cards, including four oversized sheets (11"x14"). The large sheets featured separate themes of bridges, Native Americans, ocean vessels, and harvest scenes. Below is F-1987H(c) --
this one has two engravings of the Brooklyn Bridge, including the one in question. And I notice the eBay seller has vignettes of most of the others on this sheet, so I have to assume these were all cut out. This is quite unfortunate, as only 200 of these sheets were printed.
Well, it really only has one vignette of the Brooklyn Bridge. The upper central vignette is of the Cincinnati Bridge. It was also built by Roebling. The towers were started before the Civil War. The bridge was not completed until after the war.
I don't recall where this vignette was used. Any help?
It is really a shame how these souvenir cards are being dismembered!