One of the pistols this cartridge was fired in, the Smith & Wesson Model 3, was the standard U.S. Army sidearm for two years; 1871 to 1873. As firearm and ammunition technology advanced, this cartridge was used less and less. Manufacturers ceased production around 1940.
The .44 American used an outside lubricated bullet, exactly the same diameter as the .44 Russian, but with a greater case neck diameter; this is because the .44 Russian was actually developed from this cartridge.
It is a rimmed, centerfire cartridge, with a large rifle primer. It was either Boxer or Berdan primed, and could use either blackpowder or smokeless powder. Like most other .44 caliber pistol cartridges, it fires optimally from a bore with a 1:20 twist. Bullet weights ranged from 200 grains to 218 grains.
Since it is no longer commercially produced, it must be handloaded. This can be done by shortening and reforming .44 Special cases, and using light blackpowder loads - modern powders will generate excessive pressure in the older firearms.