when we think of the protestant reformation, we think of:
martin luther, calvin, those guys, vs. the catholic church.

however in reality, there was a third group, that they both disliked.

if we imagine europe as a small video game, basically martin luther and calvin broke away, and locked down a bunch of territory pretty quickly.

so, in those realms, but mostly in places they didnt swiftly lock down, there were other groups who they themselves disagreed with. a lot. martin luther and calvin were fine using state power to enforce their views in territory we might casually say they "secured".
so if you disagreed with them, who were you? you were a third group of sectarians - meaning, mostly a coalition of the fringes. you were just part of a third folder, and lots of people in this folder had nothing to do with each other, except this odd position they were now in.

...

so, what did these groups believe in? well, lots of stuff. there isnt one thing they all had. some had a few of these, some had only one or two. just going off the top of my head, heres some things, some major and common, some really fringe and weird:

(just to be clear no one group had all these, some may be just one weird random group. DYOR)

not doing infant baptism (i.e. believers baptism)
not using state power to enforce their beliefs
pacifism
sabbatarianism (i.e. hardcore doing the sabbath, sometimes on saturday)

...

getting revelation themselves
keeping property in common or hyper communal stuff
mega apocalypticism
unitarianism
universalism (no hell)

could just keep going on here. but, lets get to the point.

theres two points:
A) the descendants of these groups, which range from full on, "yeah thats my grandfather" to "retaining a slighlt influence thats hard to spot" get lumped in with the magisterial protestant reformers

...

i went on a long quest to understand american christianity. i suppose understanding such a large phenomena in full is basically impossible. but this was a huge piece of the puzzle. if i was going to come out the gate with an explosive attention grabbing statement, it would be:
it kind of seems like

america isnt a protestant country.

america is a radical reformation country.
everything just makes sense after realizing this.