Actually the unique virtue of America is its ability to provide unprecedented economic opportunity to people of varying races and ethnic backgrounds. It’s exceptionalism is the concept of fair play that stands against the tribalism that prevails most everywhere else. Obviously America has not achieved utopia, but you seem oblivious to the incredible progress that has been made, the huge rise in the standard of living, and the tremendous progress driven by innovation and entrepreneurial dynamism.
The Civil War was 150 years ago and that ended actual slavery in the US. The Civil Rights movement was 50 years ago and that ended legal discrimination and enshrined equal treatment under law with the exception of a system of affirmative action.
There has been a huge rise in the numbers of middle class and upper class Americans of Black African lineage. I seem to recall the President of the US was a Black American. I guess that’s an inconvenient fact as far as your slavery thesis goes. Also inconvenient is that Black unemployment in America is at a record low.
There are many worrying analogies that can be made between Rome and America. But American civilization faces a whole different set of challenges.
An ever increasing pace of automation, information processing capacity, and robotics is undercutting the economic basis of future career advancement for many. We live in a society of increasing mobility and electronic communication in which people are losing their ties to one another and to their local communities. With your “America is Rome”blinders on, you may not discern these and other real problems facing America now.