Final answer:
The primary reason Puritans established colonies in the Americas was to practice their Protestant religion freely without persecution. Secondary motivations included improving their economic conditions based on mercantilism. This quest for religious and economic autonomy was a significant element in the development of New England colonies.
Step-by-step explanation:
One reason many Puritans established colonies in the Americas was to freely practice Protestantism without fear of persecution. During the 1620s and 1630s, English Puritans sought to create communities where they could adhere to their strict religious beliefs away from the perceived corruption of the English Church. The Puritans, including a sect known as the Separatists or Pilgrims, established settlements like Plymouth and Massachusetts Bay with the intention of practicing their religion freely and to propagate their beliefs.
Aside from religious motives, the Puritans were also influenced by mercantilist ideas, aiming to build prosperous economies in their colonies as a sign of God's favor and to attract further settlement. Although economic growth played a secondary role, their primary motivation was clearly ideological and religious.
The Puritans' quest for religious autonomy led to the creation of several New England colonies. They wanted to reject the Church of England's compromises between Catholicism and Calvinism, and fully implement their Calvinist-based Protestantism. Their efforts in establishing these colonies were emblematic of the broader trends of seeking religious freedom and setting foundations for self-governance which would eventually contribute to colonial discontent with British rule.