Pilgrims (1620), Puritans (1630s), Quakers, Huguenots, and others fled state churches and persecution to worship freely.
Land ownership (unthinkable in Europe), wages for labor, trade prospects, and escape from poverty/primogeniture drove the vast majority—indentured servants, yeomen, craftsmen.
Younger sons, debtors, dissidents, and dreamers saw the New World as a blank slate for glory, wealth, or a fresh start. Tales of gold, fertile valleys, and "cities of gold" fueled imagination.
These motives intertwined; a single migrant might seek all three. The resulting societies reflected this complex tapestry.