The tradition of American rifleman starts in the early post revolution times. By early 19th century the boys of Alabama might be a lot like the boys in the west for whom it was said the Canadian and the creole reached for a fusil and the American reached for a rifle.
We do have to keep in mind the precentage of American rifles that are in fact smooth rifles or rifle mounted fusils.
Alabama was in the early 19th century first growth forest. The undergrowth was less, so even in the woods you could get longer shots then you can get today.
However we have to keep in mind that few people had corrected vision. The advantage of a rifle is lost if your shooting at a brown deer shaped blob.
My left eye is 20/200 with out my glasses.( my right is 20/15 but far sighted, need bifocals to read
). I can at 50 yards keep it near or in the black with my left eye, but shoot about the same fusil or rifle with my left eye.
On another thread about Texas market hunters quotes a list of captured guns from around 1850. Many were smooth bore flintlocks. Rifles were common and preferred but I think the picture of the American frontiersman as a rifleman had some mythic qualities, I would think with a time machine we would find a lot of smoothies in the hands of frontiersman then we like to credit today.
I like smoothies and that means I can be looking at this whole thing through rosy colored glasses, after all we tend to create history in our own image.