Puritans were English Protestants who wished to reform and purify the Church of England (Anglican) of what they considered to be unacceptable residues of Roman Catholicism. In the 1620s, leaders of the English state and church grew increasingly unsympathetic to Puritan demands. They insisted that the Puritans conform to religious practices that they abhorred, removing their ministers from office and threatening them with "extirpation from the earth" if they did not fall in line.

Zealous Puritan laymen received savage punishments. For example, in 1630 a man was sentenced to life imprisonment, had his property confiscated, his nose slit, an ear cut off, and his forehead branded "S.S." (sower of sedition).

Beginning in 1630, as many as 20,000 Puritans emigrated to the colonies from England to gain the liberty to worship God as they chose. Most settled in New England, but some went as far as the West Indies.

Theologically, the Puritans were "non-separating Congregationalists." Unlike the Pilgrims, who came to Massachusetts in 1620, the Puritans believed that the Church of England was a true church, though in need of major reforms. Every New England Congregational church was considered an independent entity, beholden to no hierarchy.

The membership was composed, at least initially, of men and women who had undergone a conversion experience and could prove it to other members. Puritan leaders hoped (futilely, as it turned out) that, once their experiment was successful, England would imitate it by instituting a church order modeled after the New England Way.

The Congregational churches were at their best while the pressure of persecution served to cement them. This removed, the absence of organization left them an easy prey to the inroads of rationalism and infidelity. Before the end of the eighteenth century many of them lapsed into Unitarianism, alike in England and America.

A new problem was thus forced upon them, viz., how to maintain the unity of the denomination without consciously violating their fundamental doctrine of the entire independence of each particular church. "A Congregational Union of England and Wales," formed in 1833 and revised in 1871, issued a "Declaration of the Faith, Church Order, and Discipline of the Congregational or Independent Dissenters," and provided for annual meetings and a president who should hold office for a year.

American Congregationalism has always been of a more organic character. While persisting in emphasizing the complete independence of particular churches, it has made ample provision, at the expense of consistency, for holding the denomination together. No minister is admitted except upon approval of the clerical "association" to which he must belong. To be acknowledged as Congregationalist, a new community must be received into fellowship by the churches of its district. Should a church fall into serious error, or tolerate and uphold notorious scandals, the other churches may withdraw their fellowship, and it ceases to be recognized as Congregationalist.