here was an armory at St Aidan's School in Brookline MA that was
outfitted with rolling-block Springfield rifles from the Civil War.

The rolling block action was a Remington--Custer had one for sport shooting.
The Springfield 45/70, originally a 50/70 was a trapdoor action. Basically
Springfield just cut a "trapdoor" into the rear of their muzzle loader. The
Springfield was replaced by the Krag magazine breechloader, which was in turn
replaced by the Springfield 1903 with a Mauser type action.