I've just re-read the note in Sam Richards and Tish Stubbs' anthology, "The English Folksinger" for "When that I was weary":

Broadside ballad in the Douce collection. Also in Pepys, Crawford and Roxburgh. The Roxburgh copy tells us that this ballad was printed c 1690. The Virginia Company was formed in 1606, and the government offered incentives for traders and colonizers to go there. One way of providing labourers for the colony was simply to kidnap and sell into slavery any victims that could be conveniently seized, and petty criminals were given transportation sentences as well. The system had ceased by the end of the century, although white slavery (euphemistically referred to as "indentured servitude" in old history books) continued for some time.

Kitty