why did puritanism end?

Answer 1

I'm not sure if you're referring to American Puritanism or English Puritanism. American Puritanism certainly came directly from the English; our Puritans had fled England first to Holland, then to the New World so they could practice their faith without persecution and without the influence of the wider, non-Puritan world around them.

(An interesting historical detail that points to why and how Puritanism itself ended is this: our Puritans fled to Amsterdam where they found other Puritan groups who had fled for the same reasons before them. However, these groups had already begun to develop theological differences one from one another and certainly from our group. The Puritans who were to end up in America were scandalized sufficiently to move again to Leiden to isolate themselves from their fellow Puritans!)

The goal was doomed from the start: not even the Mayflower community was exclusively Puritan, and this was the source of a lot of trouble in the Plymouth community.

Internal community differences, the influence of the outside world, and the inexorable march of time eroded the ideal Puritan community envisioned by its founders as early as the second generation. But many of its theological tenets and premises remain embedded in American Protestantism. Without a doubt, this small community contributed much of the essential warp and woof of our American culture.

Answer 2

It did not end, and is still practiced by many today. To days Puritanism is not as orthodox as its predecessor, due primarily to its archaic practices and the infiltration of many into similar denominations which offered more freedom.