LOL!
factoid about the caisson and horses:
-The caisson and caparisoned horse:
Perhaps the most indelible image of a presidential state funeral is the procession of six horses pulling the black artillery caisson that bears the flag-draped casket. Only the three horses on the left are mounted, a tradition dating to when one artillery horse in every pair carried provisions instead of a rider.
Behind the caisson is another riderless horse, with an empty saddle and the rider's boots reversed in the stirrups, symbolizing a warrior who will ride no more. The caisson and caparisoned horse are central in the Wednesday evening procession to the Capitol. The caparisoned horse for Reagan's procession is Sgt. York, a solid black standardbred retired from the racetrack.