The Spanish and Portuguese were not very effective about colonizing the New World, despite finding gold and silver and claiming land. The London Company arrived about 1611 with indentured servants. Life expectancy was as young as twenty-one, although food supplies were better in the New World. Land was cheap and available to most immigrants.
The Plymouth Colony in 1623 turned itself into a private property group which flourished as a settlement. Many colonies were run by proprietors appointed by kings. Opportunities in the New World were much greater than in the Old. Many male immigrants had had neither homes nor fathers in Europe. Thus, being an indentured servant was more likely than being an apprentice.
Lecture 3 of 9 from Mark Thornton's The Economic History of the United States.