Of course the United States on its foundation was essentially a compromise between the plantation States of the South and the evolved puritan society in the north, which eventually industrialised. Obviously these two cultures weren't entirely compatible and eventually went to war with one another. Then, after the Civil War, the United States went through a few decades of mass immigration, in which it received lots of people from non-English speaking Europe. Germans, Italians, Irish, eastern European jewry, etc. Eventually, around 1920 the US closed its borders to further mass immigration. The people of the immigrant wave melded into American society, and by the end of the second world war, they were the dominant American culture. The demographics of the country had changed, but it retained its core values. These are the people of The Brady Bunch and I Love Lucy. In the late 1960s, the gates opened again, and mass immigration started again. This time people came from different places: Latin America, India, China, but in fact a huge preponderance of places. We seem to be where the previous wave was in perhaps 1900. America's demographics are swirling around again, and eventually a new culture will come out. This is what the demographic trend of population growth is about. Inevitably a less European America is coming out of this. However, I don't see any reason why this new America will even lost the core values of the country. These withstood the last demographic change. As far as I can see., America will always have democracy and free speech.