I think they come from the European Humanism and Enlightenment, they are not American specific. Equality in rights and opportunities, social liberalism, economical liberalism, religious/origin tolerance, rationality, democracy.

There's some overlap between the two.

I think what makes something some country's values is either the government publicly adopting or enough of the population doing so. That doesn't mean anyone is actually living up to those values. Might not even be trying.

And then there's the question, their values from whose perspective? Americans might say thing X is their value but outsiders might look at them and conclude their value is Y. So there's no one set of coherent values that hold true from all perspectives.