About a year earlier the 72nd PA was also still using left and right flank markers/general guide flags. The left flank flag went at auction a little over a year ago, and I have a photo of it somewhere that was posted here in the past. Being as the 20th Corps came from the Army of the Potomac (like the 72nd PA), is doesn't surprise me that it still had some units using these markers that were left over from their time in the eastern theater. I would be curious to see if new issues of these were made after this capture though.

Josh Bucchioni