Hm, not really. That would make you a second-generation immigrant. [1]

First-generation immigrants are folks who are born outside the US and naturalize. "In the United States, among demographers and other social scientists, 'second generation [immigrants]' refers to the U.S.-born children of foreign-born parents."

Not in the strictest sense, but it's not the bright line you're making it out to be either.

[1] https://en.wikipedia.org/wiki/Immigrant_generations

This is incorrect, 90% of Americans are not immigrants. Please stop spreading misinformation.

Unless your ancestors were in the Americas before Columbus arrived, you're an immigrant. First generation, tenth generation, a hundred generations from now, it doesn't matter. Your great great grandfather landed at Plymouth Rock? You're not native.