I was thinking about how some of my recent ancestors' religious affiliation seemed to be based on geography and class (in an aspirational sense) more than on family tradition or ethnic background, and then I started wondering how that might have worked in earlier phases of American religious history. For instance, my paternal grandparents grew up in small towns and I think were brought up Methodist, but by the time they got married in Cleveland, they belonged to an Episcopalian parish because, according to my dad, they hoped to benefit from the superior prestige of Episcopalianism. But that distinction has to postdate the Second Great Awakening, right? So how did people choose their church before that?
I've also been thinking a lot about the wealth of families like the Schuylers and the Revolutionary loyalties of Philip Schuyler, father of my current historical crushes Elizabeth Hamilton and Angelica Church. In a region full of rich Dutch people (but not so many other kinds of Calvinists, as far as I know), would Reformed Protestantism have held any attraction for people who weren't Dutch, or would it have been too Dutch or too old-school even for people of Dutch descent?
It is clear that all of New England was Calvinist. Massachusetts, Plymouth, New Haven and Connecticut (including Long Island until 1664) had established Congregational (Independent) churches. Rhode Island was Calvinist but had no established church. The Baptist and Quaker congregations in RI are best viewed as Calvinist churches that were most similar to the more heterodox English Independent churches of the 1640s.
The settled parts of New Hampshire and Maine were generally Calvinist.
Between 1620-1704, the CoE was excluded on the theory that the reformed churches of New England were simply the properly reformed expression of the CoE and that the charter issued by Charles I in 1628 granted them the right to decide the proper expression of the CoE within their jurisdiction. The Catholic Church was excluded on the theory that it was not a true church.
The Dutch Reformed Church was viewed as a sister Calvinist church by the Congregationalists and Presbyterians of New England.
In 1664, the English seized New Netherlands from the Dutch at the end of the Second Anglo-Dutch War and established the CoE as the religion in the proprietary colony of New York. The proprietor was Charles II's brother, the Duke of York.
Virginia had been a crown colony since 1624 and the CoE was the established church but Calvinists were present in some numbers. Maryland was founded as a refuge for English Catholics by Charles I in 1632 with no established church but that did not last. Maryland became a mixed CoE and Calvinist colony after 1650.
Pennsylvania was founded as a Quaker colony but English Quakers followed basically Calvinist forms of worship.
The Scots-Irish who began arriving after 1710 were generally Presbyterians who easily blended with the already established Calvinist churches in the American colonies and extended calvinism into the backcountry from New England to Georgia.
The Carolinas were proprietary colonies established by Charles II in 1663 and were generally CoE.
All this is from volumes I- III of JG Palfrey's History of New England (1858). Palfrey usually treated religious matters under easily identifiable sub-headings in the table of contents.
Methodism began as an attempt by the CoE to reintegrate low church Presbyterians and Congregationalists (Independents) back into the CoE.
In general, you are right about geography and class. At the time of the Revolution, royalists did tend to be CoE; Whigs tended to be coastal Presbyterians and Congregationalists; and republicans tended to be rural and backcountry Calvinists of all lights.