The last smoothbore musket accepted into US service was the Model 1842. It was also the last .69 caliber US firearm adopted.
The Minne ball was invented in France about the same time that it was adopted.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.