It’s always interesting to me how long a lifespan people assign to “Puritan New England”. Of course, there are two kinds of “Puritan” being described: the days of the Puritan colonies and a set of behaviors that people who were not Puritans describe as “puritanism”. People tend to describe New England society as Puritan from 1620 to about 1950—a much longer span than is warranted by fact. The real lifespan of Puritan New England is 1630 to about 1720.
We say 1630 because the Pilgrims who arrived in North America in 1620 were not Puritans (see here for more on that); it was the group who arrived in 1630 who began Puritan colonization. The colonies founded by these Puritans were based on the religious practice of Congregationalism, and this meant three things that are the main characteristics of Puritan New England: 1) the colonies thrived on and required religious homogeneity; 2) a proto-democratic political system was necessary to protect the unique society created in America; and thus 3) the colonists devoted themselves to evading direct rule from England in order to maintain that political system. For as long as these three characteristics were unchallenged, Puritan New England existed.
How long was that? Not very long. The aftermath of King Philip’s War (1675-6) brought political discord between the Puritan colonies, which brought on direct rule from England, first in the form of the Dominion of New England (1686-9), during which time the Puritan colonies of Massachusetts, Vermont, New Hampshire, Connecticut, and Rhode Island were restructured into one mega-colony (along with New York and East and West Jersey). It’s important that during the Dominion the Puritans were enraged not just by the promotion of Anglicanism over Congregationalism but also by the destruction of the Puritan legal and political system: legislatures were no longer popularly elected, land titles were revoked, and a royal court with no jury was set up in Boston to enforce the Navigation Acts.
The Dominion was overthrown after the death of King James II, but English direct rule did not end. The Puritans who had overthrown the Dominion immediately pledged their loyalty to the new king and queen, William and Mary, and William opened the Puritan colonies to outsiders. Non-Puritans began settling in New England in large numbers, and their religious practices were protected. By 1691, when the Massachusetts Bay Colony’s charter was overthrown and it became a royal colony with a royally appointed governer, true Congregationalism was rapidly becoming a blast from the past. Its dominance was certainly at an end, as it became simply one religion amongst many others.
Of course, it took decades to completely unseat the old religious ways. But an important shift was occurring after 1689: much of the fervor originally associated primarily with religion in Puritan New England was being gradually but steadily extended to politics. Note that the Dominion and the charter revocation dealt a fatal blow to pure Congregational practice but strengthened the old Puritan political dogma. What the people of New England held on to was proto-democracy: a popularly elected legislature, juries made up of local citizens, and the right of towns to hold their political town meetings.
So by roughly 1720-30 the shift was fairly complete. New England was no longer Puritan, it was polyglot with a Puritan past and a powerful Puritan legacy that newcomers and non-Puritans were very aware of. Congregationalism remained the majority religion, and people in the Congregational church were very committed to its original principles as codified in 1649. But politics began to supersede religion as the defining characteristic of the region, and New England would lead the way into the age of Revolution.
The echoes of the old way, the true Puritan New England that only existed from 1630-1686, were heard long after the fact, of course, and it may be the very brevity of the actual Puritan moment that made it so powerful an image for later writers, religious leaders, politicians, and historians. But any reference to “Puritan New England” after 1730 at the latest, and 1720 more likely, is mostly inaccurate.