Black powder rifles are not very popular these days due to how time consuming they are to shoot, which is unfortunate because they are lots of fun to shoot.
The Military Arms channel takes a look at some American Civil War era rifles and their impact on military tactics.
Both of these firearms can be purchased as reproduction firearms.
If you have not fired blackpowder muzzleloading firearms, definitely try and find an opportunity to do so. It is a very unique and fun experience. Due to how the powder ignites, the recoil is more of a push than a punch, allowing shooters to shoot large caliber bullets, like .50 cal bullets, and it is a lot of fun.