Except that zheng he ,a white-headed eunuch of emperor Zhu Di,once made the voyage to Southeast Asia, South Asia, and East Africa,there wasn't any contact to outside world because emperors in ming closed the country off to international interaction afterwards.out of vanity,they believed our country was the most advanced one and needn't others.of course,they were too stupid.

Yes, somewere in the 1400's they came in contact with america. There is a book about it.