Very cool! I have half of one that's very similar, if not identical. Dug it in a hut on a yankee winter camp. It was split down the middle, so just found one side of the bowl. Congrats!
Bottle diggers frequently find these. They are rather common if you find civil war period dumps. I have dug privies around old taverns and have found intact pipes. I have several shoe boxes full of bowls and stems . Some are very ornate.