The U.S.A. is a Nation of Immigrants. Really?
A Common Expression
What is meant by the proposition “We are a nation of immigrants.” It is common expression; one especially favored by politicians. President John F. Kennedy used the expression many times; for example, when addressing the 50th Annual Meeting of the Anti-Defamation League in 1963.  Moreover, he wrote a book with that title which was published posthumously. 
More currently, President Barack Obama has said it on many occasions. For example, in a naturalization ceremony at the White House on July 4, 2012, Obama said, “[W]e are a nation of immigrants. Unless you are one of the first Americans, a Native American, we are all descended from folks who came from someplace else—whether they arrived on the Mayflower or on a slave ship, whether they came through Ellis Island or crossed the Rio Grande.”
To understand the proposition that we are a nation of immigrants, I think we first should ask “What is an immigrant?” The on-line Oxford Dictionary defines “immigrant” as “[a] person who comes to live permanently in a foreign country.”  The on-line Merriam-Webster dictionary defines “immigrant” as “a person who comes to a country to take up permanent residence.”  From these definitions, I think that what it is to be an immigrant to the U.S. is clear. It is to be a person who comes to the U.S. from a foreign country to live here permanently.
How many of us are truly immigrants?
However, how many of us in the U.S. came here from a foreign country? I didn’t. Nor did my parents. Nor did my grandparents. I know that some of my ancestors came to the British colonies in America in the 1700's before there was a United States of American. It may be that all of my ancestors who migrated to the geographical area that is now the U.S.A did so over 200 years ago. So, I am not an immigrant according to the definition of “immigrant” given by the on-line Oxford English Dictionary and the on-line Merriam-Webster dictionary. Moreover, although I am descended from immigrants to this area, I do not identify myself as such because they came here so long ago. Being an immigrant is just not part of my identity. I am an American. That’s my identity, pure and simple.
I have digressed. Let us return to the question, “How many of us in the U.S. came here from a foreign country?” Surely, the authority for answering this question is the Census Bureau. According to its “2009 American Community Survey, the U.S. immigrant population was 38,517,234, or 12.5 percent of the total U.S. population.”  Thus, about 88% of our population are not immigrants.
Serves a Political Agenda
So why do presidents, other politicians and other social-minded people say so often that we are a nation of immigrants when clearly we are not because the overwhelming majority of us were born in this country and thus are not immigrants? That is an important question, because we cannot seriously entertain the idea that those making the assertion do not know the dictionary meaning of “immigrant.” Clearly then, they do so not out of ignorance but to advance some political agenda. The nature of that agenda, however important, is beyond the scope of my present essay, which is simply to understand what is meant by the proposition “We are a nation of immigrants.”
Expanded Definition of "Immigrant"
Although we may not know the motives of those who assert that we are a nation of immigrants, we easily know their method. It is to redefine the word “immigrant” to serve their purposes (whatever they may be). Redefining words to suit one’s political purposes is a well-know practice. The change in definition is clear when we look at Obama’s statements cited above. The meaning of “immigrant” is expanded to include anyone who is a descendant of someone who came from somewhere else, i.e., a true immigrant. According to Obama’s definition only Native Americans are not immigrants.
We shouldn't accept the expanded definition - Reason 1
If we accept Obama’s definition of “immigrant” (and similar definitions by many others), then it follows that we are indeed a “nation of immigrants.”
However, why should we accept the expanded definition of immigrant? There are good reasons not to. One is that we would have to find another word for the useful concept of a class of persons who come from one country to live permanently in another country. That is, we would have to find another word for the current dictionary meaning of “immigrant.” Simpler is better, and it would be simpler to keep the current dictionary definition of “immigrant” and to invent a new word for the concept of a class of persons who either come from one country to live permanently in another country, i.e., “immigrants,” or are descendants of immigrants. However, that will not be done because it would not suit some political agendas.
We shouldn't accept the expanded definition - Reason 2
A second reason for not accepting the expanded definition of immigrant is that is trivial. It is trivial because every nation in the world is a nation of immigrants. Thus, to say we are a nation of immigrants is to say nothing distinctive about us. If every country is a nation of immigrations, why boast about it? What’s the point?
In his speech cited above, Obama excluded Native Americans from being immigrants to the geographical area that is now the United States. However, there is no valid reason for doing. Science tells us that the peoples we call Native Americans migrated to the geographical areas that are today the Americas—North and South.  Theories differ on when they migrated to the Americas with some arguing that they migrated as early as 40,000 years ago and others arguing they migrated no earlier than about 15,000 years ago.  In any case, the indigenous peoples of the Americas migrated to the present day Americas a very long time ago. Some might argue that they migrated to the Americas so long ago that they shouldn't be considered immigrants. However, what rule (major premise) justifies this argument. Obama included the descendants of those arriving on the Mayflower as immigrants to America. The Mayflower landed in present day Massachusetts in 1620, or 394 years ago. Thus, if one of your ancestors was an immigrant 394 years ago, then according to Obama you are an immigrant too. We may if ask if you would be immigrant if you had an ancestor that immigrated 500 years ago? Why not? 1,000 years ago? Why not? 10,000 years ago? Why not? And so on. Once you expand the definition of immigrant to include descendants of real immigrants (i.e., dictionary definition immigrants), then there is no rational limitation of how many years you can go back. Any limitation would clearly be arbitrary.
Thus, according to the expanded definition of “immigrant” everyone in the world is an immigrant, except perhaps for a small group of people who reside in the area in Africa when homo erectus first appeared.  Even then, if an inhabitant of this area is a descendant of anyone who was born outside the area, then he or she too is an immigrant according to the expanded definition of “immigrant.”
Let me conclude. First, there is no good conceptual reason for expanding the definition of “immigrant” to include descendants of immigrants. To do so obscures clear thinking for the purpose of serving some political agenda. Second, the statement “we are a nation of immigrants” is trivially true, where the meaning of “immigrant” is the expanded definition. It is true also of every nation in the world. So why waste time making speeches about it?