I find this rather hard to believe.
How many colonies had, as their official church, the Episcopal church?
Virginia did, and it remained established after ratification of the Constitution. (And disestablishment was a slug in the financial guts.) Mind you, my impression is that one could believe a lot (or a little) and still be an Episcopalian. It wasn't a very theologically specific church.
“How many colonies had, as their official church, the Episcopal church?”
Of the original 13 in North America? I would wager that, other than Maryland, which was specifically established as a Roman Catholic enclave, the other 12 were officially Anglican. Even the Puritans of New England were part of the established Anglican church—wishing to purify it from Romanism, after their (stricter than Calvin) Calvinism. Of course in America, even as colonies, things were laxer than in the old country, and over time at least, more tolerance was offered to “sects” to practice Christianity as they saw fit.
Massachusetts under the puritanical Puritans for example, did allow other Christian groups...as long as they weren’t Quakers, (wild Pentecostals back then...) who were seen as beyond the pale in the 17th Century (a few got hung on Harvard Square, I understand). Pennsylvania and Maryland were the most tolerant though, hence we see the establishment of Quakerism, under Penn, as well as freedom for other even foreign sects (Mennonites and Moravians for example) in both states.
I know one reason for the term “meeting house” is that it was illegal in colonial days, in most colonies, to refer to places of meeting for other than Anglicans as “churches.” Hence our vocabulary today of the “Quaker Meeting House” even in places like Pennsylvania.
Oddly enough, most Americans don’t know that the established colonial churches CONTINUED getting state government support after 1776, mostly up until the 1820s and 30s. Since the federal Constitution only applied to the federal government, it took state legislatures to change their own state constitutions to outlaw official state churches...and the ACLU was nowhere to be found.