I don'y know much about the Sharps, but for the Rolling Block you need the book:"TheMilitary Remington Rolling Block Rifle" by George Layman. According to this, the US Government (The North!) ordered about 20,000 pieces, most of which were delivered too late for the war and were sold as surplus.
I am very fond of my rolling block and shoot it a lot, but I don't rate it as a soldier's rifle.  
There are two problems, firstly, it is sensitive to dirt: a bit of grit behind the case rim will prevent it fully chambering and, unless the case is fully home, it will not fire; secondly, when loaded it is cocked and can only be made safe by manually lowering the hammer to half thingy. Doing this in cold, wet weather must have resulted in accidental discharges from time to time.
Fred.