Rollin White was the inventor who patented the bored-through cylinder in the US, and sold an exclusive right to this patent to Smith & Wesson. They would use it as the basis for their own work with self-contained cartridges (White’s patent was originally intended as a way to load paper cartridges form the rear of the cylinder), but when the Civil War broke out White was in an odd position. Having sold an exclusive license to his idea to S&W, he could not sell guns utilizing that system himself. He was involved in the formation of the Rollin White Arms Company in 1861, and would make .22 rimfire revolvers, but only for purchase by S&W, who acted as the seller/distributor for them.
White did produce one other model of pistol in an attempt to chase in on the demand for arms during the war, and this was a single shot pistol that thus did not infringe on his licensing agreement with S&W. The design was very similar to a Smith & Wesson revolver, but with a single shot tip-out breechblock in place of a cylinder. Two versions were made, a small frame in .32 rimfire and a large frame (as we are looking at today) in .38 rimfire. The small type sold reasonably well, with 3,000 made – but only 200-300 of the large type were built. Most likely, it was simply too large for people to justify as a single-shot pistol.