I once used the Perry ACW cav as Hollywood US Cavalry. I wasn't worried about historical accuracy, just painted them to suit a John Wayne idea of US Cavalry, so take my comments with a grain of salt!
Comments:
-all of the figures have sabres moulded on. You may wish to carve these off.
-there aren't enough slouch hats for all the troopers. I ended up giving the bugler a kepi
The plastic is pretty forgiving, so conversions are quite feasible.