The man who is most commonly credited with finding the first cash crop that could make the Virginia colony economically viable was a man named John Rolfe. In popular culture, he is more commonly known for the fact that he was the man who married Pocahontas. However, it is fair to say that his more important contribution to American history had to do with tobacco. Tobacco was the cash crop that Rolfe introduced to Virginia.
Rolfe arrived in Virginia in 1610, very early in the colony’s history. He set about looking for an economic basis for the colony and felt that tobacco could be grown there and exported to England. However, the variety of tobacco that grew in Virginia was too harsh. So Rolfe got seeds from the West Indies and planted them in Virginia. They grew very well and eventually became the basis of a booming trade with England.
Thus, the man who provided Virginia with its first cash crop was John Rolfe, who brought tobacco (at least as a viable staple crop) to the colony.