Here is what I have always thought: My grandparents, on both sides, immigrated from other countries. (Not sure of their citizenship status, or even if that matters.) They were the first 'generators' of future Americans, my parents, were second generation, so that makes me 3rd generation. Is this correct?
If you believe the government, first generation Americans are foreign born:
The first generation refers to those who are foreign born. The second generation refers to those with at least one foreign-born parent. The third-and-higher generation includes those with two U.S. native parents. — US Census Bureau
If you look at usage, then it's mixed. Merriam Webster neatly shows this by listing both:
- born in the U.S. —used of an American of immigrant parentage
- FOREIGN-BORN —used of a naturalized American
First generation Americans are the first generation to be "American" and that's what makes it unclear. Can an immigrant become American? It depends who you ask.
With other words, there is no question: a first generation college graduate has parents who didn't graduate college, for example.
See also ThoughtCo.
The usual phrase is First-Generation Immigrant.
"American" doesn't mean anything in that context.
Immigrants who come from another country are First-Generation immigrants.
Their children are Second-Generation immigrants (Nisei in Japanese).
Their children are Third-Generation immigrants (Sansei).
And so it goes.
Becoming an American means becoming a citizen, which involves filling out forms,
taking tests, and fulfilling other requirements. Immigrants of any generation can become citizens.
Taken at face value, apart from any context, the phrases of the form nth-generation American (or Canadian, Australian, etc.) are ambiguous, because the word American is itself ambiguous. It can mean:
(1) somebody who has lived a significant part of his or her life in the United States, and whose life has been significantly coloured by American culture, or
(2) somebody who was born in the United States, or
(3) somebody who is a citizen of the United States.
If by American one means (1), then the people who immigrated into the United States are themselves first-generation Americans, their children are second-generation Americans, and so forth. If by American one means (2), then the children of the immigrants are the first generation. If by American one means (3), then the counting depends on whether the relevant immigrants were naturalised.
Now, I expect that, outside specialised contexts, in casual day-to-day conversations, most people mean by American something like (1), because in ordinary everyday interaction with people, their places of residence and cultural affiliations are more salient than the places of their birth or their citizenship. From that it follows that, in the absence of contextual clues that would indicate otherwise, it is most reasonable to interpret first-generation Americans as standing for those who immigrated into the United States (regardless of whether they are naturalised), second-generation Americans for their children, and so forth.
However, because terms of the form nth-generation American are not entirely unambiguous, it may be wise to avoid them and convey such information by some entirely different language, such as 'Her parents immigrated from . . . and she was born here' or 'It was his grandparents that immigrated into this country from . . .'.
Incidentally, eschewing the nth-generation terminology also avoids the awkwardness that arises when one tries to apply it to those who immigrated with their parents (which may be compounded by their having siblings born after the move).
Of course, if one is in some specialised context, in which such terms are explicitly, stupulatively defined, then one should use them in accordance with these field-specific definitions.
The question asked only about the phrases of the form nth-generation American and not about the phrases of the form nth-generation immigrant, but the latter have been introduced into the discussion in the other contributions to this page, so something need to be said about them as well. Wikipedia has an article on Immigrant Generations which acknowledges that terms of the form nth-generation immigrant are used in sociology and that
the categorization of immigrants into generations helps sociologists and demographers track how the children and subsequent generations of immigrant forebears compare to sections of the population that do not have immigrant background,
but also points out that
the term second-generation immigrant attracts criticism due to it being an oxymoron. Namely, critics say, a "second-generation immigrant" is not an immigrant, since being "second-generation" means that the person is born in the country and the person's parents are the immigrants in question.
If one wanted to excuse the sociologists' use of these terms, which is from a lay person's viewpoint bizarre, one could argue that it may be a result of their taking communities as their primary objects of investigation, rather than individuals as individuals. It is not unnatural to use the terms such as immigrant community or immigrant family for communities/families whose character is shaped by immigrants, even if some of their younger members are not themselves immigrants. On this reasoning second-generation immigrant, which is absurd when taken literally, can be regarded as a shortening of second-generation member of the immigrant community.