I would say we can answer this in two ways.
One is that we have what I consider a uniquely American philosophical lineage. They are generally not formal or technical philosophers, but they are influenced by them. They are also not academics but generally writers, activists, and so on. Examples would be Henry David Thoreau and Ralph Waldo Emerson.
I would also say we have an American lineage of philosophy that is innately pragmatic. These philosophers were generally influenced by psychology as much as formal philosophy and their work was really for the direct application and benefit to man. Examples would be Henry James and John Dewey.
And I would say that we have a uniquely American lineage of political philosophy. Our whole political experience in American is really an expression of political philosophy. Thomas Jefferson was a political philosopher. Full stop. We have political philosophers as part of our political experiment all the way to the present. We also have people like John Rawls in the academic setting.
The other answer is that your question really speaks to a schism in 20th century philosophy. The schism between analytical and continental philosophy.
Continental philosophy is just that-- the late modern philosophy of the European continent. It is largely Kantian in influence, rejects that science is as valid a means of understanding the essence of things as philosophy, and really emphasizes such things as human agency, meta-philosophy (the philosophy of philosophy or philosophical method), and historicity. It is very influenced by Kant, Hegel, phenomenology, and existentialism.
There's a lot that can be said but in the 20th century we see a schism and the formation of a whole new movement in philosophy called analytical philosophy. Historically and geographically that is more of an Anglo-American thing. It developed from the logical positivists like Bertrand Russel and Alfred North Whitehead. Philosophers of mathematics like Frege and Carnap. Wittgenstein who picked apart language like no other.
And that's really a big piece of analytical philosophy. What they call the "linguistic turn". Philosophical investigation relying less on the formal philosophy of the continental philosophers, more on mathematical logic, the philosophy of language, and the philosophy of consciousness. Also on the findings of science.
So many of our great American philosophers are in this analytical tradition. Which in many ways is eclipsed by the continental tradition. William Van Ormand Quine is probably one of the most influential philosophers of the 20th century and solidly in the American analytical tradition. There are plenty of high profile analytical philosophers as public as any philosopher can be, and they go across all philosophical inquiries from political philosophy to philosophy of mind, science, religion, and so on.
