Conversation:

This entry was quite thorough , but I’m afraid you left out one contender. I don’t blame you because it is quite generally unknown to westerners. As mentioned in A1325044, Polynesian sailors from the Marquesas probably reached the mainland of South America around AD 300 or so. Suppose its a bit late to be adding any more at this point though.
-MotDoc

AUGUST 1619;
English settlers in James-town, Virginia, purchase 20 black Africans from a Dutch frigate. although these particular Africans are treated as bond servants, it is not long before European colonist in the North America are treating black Africans as slaves; they are imported, bought, and sold as though material property. and their children are condemned to a life of slavery. Most of these black Africans are held in the Southern states, but many thousands are also held by Northerners-and many Northerners profit directly and indirectly from the slave trade, in the ensuing decades, as the number of slaves increases to hundreds of thousands, slavery itself evolves into a legally sanction system.

Interesting, but a bit out of place here, TLG!