Thanks for posting the pics, Joe. This is one of my favorite ACW photos for a few reasons, not the least of which has to be the photographer's admirable attempt to capture the image of an entire "flying artillery battery." I can just hear him telling the troops that they had to remain as still as possible for the picture to come out successfully; it's a shame that some of the horses evidently didn't want to cooperate with him on this day. In my opinion, the fact that all six guns appear to be 3-inch ordnance rifles, also doesn't hurt the picture's appeal .
Battery M, 2nd U.S. Artillery, at Fair Oaks, VA, June 1862.