I agree with onecat to some extent that history builds a culture. History is the treasure of experience. America, as a country, does not have a long history. However, interestingly, American culture has the same, if not more, depth and broadness as every other culture survived with a long history. All the immigrants from every part of the world bring their bodies as well as their cultures into America. In this sense, the histories that happened in other areas can now be inherited by a culture living in a different area.
I like to read history books and philosophy books. From what I saw, I believe American culture did absorb most essence from European histories. Moreover, it had its unique experience of accomodating different populations, which is worth learning for other cultures. For example, I don't believe black people could have the same kind of respect if they were in current China (just imagine how many Chinese here in US have disrespect towards hispanic and black people). So, overall, American culture is successful in rooting in the history of human kind. It has lead the new way for human beings, that is to learn from others without the boundaries of country, race, and culture. Whoever thinks superior of one's own culture will be left behind in this new world, as our ancestors did a few hundred years ago.
BTW, onecat said her strong emotions in her articles reminded her that she was still young. However, at the same time, the stubbornness and eagerness to judge, in my mind, is a sign of aging in psychology (most senior people are conservatives). A young heart is always ready to accept not judge. So a late "happy birthday!" to onecat, and wish you can live younger (studying science, as you mentioned, definitely help keep you young; since accepting and learning is the way of science).