Jamestown was successful largely because of the introduction of tobacco as a cash crop. While strong leadership played a role in the colony's short-term survival in the years following its foundation, it was its ability to make money for its founders in London, the Virginia Company, that ensured its long-term survival. Following the introduction of tobacco from colonies in the Caribbean by John Rolfe, Jamestown began to flourish economically as demand for tobacco continued to rise in Europe. Virginia planters began to aggressively acquire larger tracts of land and to import indentured servants (and eventually enslaved people) into the colony to work on them. The introduction of tobacco as a cash crop not only led to the long-term economic success of the colony, but also shaped its social structure. Over time, the politics of the colony were dominated by wealthy planters who developed as a tightly-knit elite class.