Pierre Gassie (aka Pierre Gassies) was the first known Gassie to take up permanent residence in Louisiana, after arriving from France in 1823.

You can read the story of Pierre here.

Did Pierre have other male children?
At least one document suggests that there were perhaps 2 other male children that died at a young age, one Jean and yet another Pierre. It would not have been unlikely to have given the name Pierre to more than one child, based on evidence of how other French families were using names at the time.