sentences:  One modern writer, however, estimates that 7 to 10 percent of the colonists returned to England after 1640, including about a third of the clergymen.A group of separatist Puritans had fled from England to the Netherlands because they were unhappy with the insufficient reforms of the English church, and to escape persecution.After a few years, however, they began to fear that their children would lose their English identities, so they traveled to the New World in 1620 and established Plymouth Plantation.