The first “boatload” were slaves who were pirated from a spanish slave ship, and brought to virginia and sold.
They were not the first slaves in virginia either, but history is not “our” strong suit.
The arrivals in 1619 were not sold as “slaves” but as indentured servants which was slavery for a usually 7 year period and could be extended if the servant ran away or was caught up was caught up in some other infraction but it was not officially slavery.