Relations between china and the united states, china and the united states, what is different?

The US consists of a polyglot of many races, ethnic groups, cultures, nationalities, languages and spiritual philosophies. Comprising large numbers of people, who have emigrated from many different areas of the world. 
  The US has only existed as a nation for about 240 years and has undergone major cultural shifts throughout its' very short history.
   While China is far more racially, culturally and linguistically holistic. It is one of the few countries in the world with a long standing continuous  culture. Origins of which began over 4,000 years ago.