Particularly in the years after 1630, Puritans left for New England, supporting the founding of the Massachusetts Bay Colony and other settlements. The large-scale Puritan emigration to New England then ceased, by 1641, with around 21,000 having moved across the Atlantic. This English-speaking population in America did not all consist of colonists, since many returned, but produced more than 16 million descendants. This so-called "Great Migration" is not so named because of sheer numbers, which were much less than the number of English citizens who emigrated to Virginia and the Caribbean during this time. The rapid growth of the New England colonies (~700,000 by 1790) was almost entirely due to the high birth rate and lower death rate per year.