i also don't know much about a fair amount of weapons, unless of course i've specifically looked them up. belfast mentioned that smokeless powder is too dangerous to use in a muzzle-loading rifle. as far as i know, though, the Springfield isn't muzzle-loading and the first model of it was a rifled musket dating to 1855. any way you slice it, that'll make it predate the Civil War, and if smokeless powder has been invented by then, i'd say it's entirely possible for either that model or the one that was made in 1861--and would therefore be used in the Civil War--to be designed for use with smokeless powder
Actually the Springfield was a muzzle-loader. That said if someone comes up with smokeless powder and a rifle that would work well with it at around the same time in 1855, assuming it was scientifically possible, then it would be feasible to see it in use during the Civil War. The Dreyse needle gun, a breechloader, was invented decades before so it's not out of the realm of technical possibility for someone to come up with a breech-loading rifle that works well with smokeless powder. The question is if someone at the Springfield Armory or Colt, another likely suspect for coming up with an American breechloader around that timeframe, is aware of the Dreyse and figures out how to make a workable rifled variant.