Church Affiliation Colonial and Now -- Sightings (Martin Marty)

Here.  A taste:

So how were things in the good old days? A consensus questioned by a few serious scholars—Patricia Bonomi among them—is that fewer than 20 percent of the colonial citizens were active in churches. Change came after 1776, so that, in one common estimate, church participation jumped from 17 percent to 34 percent between 1776 and 1850. A better past, more illuminating for comparison in present concerns, is between the early 1960s, when participation crested, and today.

I'll have to check the footnotes; but I do seem to remember more than one authority claiming this may be a lowball. The truth usually lies somewhere in between. On the one hand the Christian Nation notion that virtually every American citizen at the time was an orthodox Trinitarian, church active Protestant is bogus. There were plenty of nominal, unchurched men more likely to be in a tavern on a Saturday night than in a Church on Sunday. But the exact numbers? What constituted a statistical majority? Not sure.