Ok, so you admit that the USA decided they do not want chinese, they don't like chinese and before 1960, no way in hell were they going to let chinese in (except for brides US GI's wanted to bring home as wives).
Is there anything wrong with that? Have Chinese ever wanted Africans? Will China ever admit tens of millions of Africans? By your non-answer, you've admitted that the Chinese have never wanted Africans and probably will never want them by the tens of millions.
Perhaps you could elucidate the kindness the China supplied to the U.S. that was not self-interest.
You should study the history of the war during the 30s in Asia....