That’s a different situation considering the Irish language was created before there even was a united Ireland. We can trace the history of how English came to America, and it came from the English people. We can’t trace the history of how the Irish language spread across Ireland because it predates history.
Like I said, while semantically imprecise, yes, we did get the English language from the English.
Did Northern Ireland adopt the Irish language from Ireland after the treaty then?
That’s a different situation considering the Irish language was created before there even was a united Ireland. We can trace the history of how English came to America, and it came from the English people. We can’t trace the history of how the Irish language spread across Ireland because it predates history.