Question about the formation of the Protestant Canon of Scripture

A reader writes:

Since I last wrote to you (about Dum Diversas), I have been received and confirmed into the Church. Thank you for your kind and respectful answers to my honest questions, and thank you so much for writing By What Authority. That book was the nail in the coffin of my Protestant life 😉

I have a question I hope you or your readers can answer for me, because I can’t seem to find anything concrete about it. (Maybe I’m just a poor researcher.) When I was learning about the deuterocanon (including by reading several of your articles about it), some sources noted that Martin Luther, along with denying the inspiration of the deuterocanonical books, also rejected NT books like Hebrews, James, Jude, and Revelation. Yet, all of these books appear in every modern Protestant Bible. One of these articles described it as “an accident of history” that the NT books remained while the OT books were jettisoned. I’m really curious for more information about this “accident of history.” I don’t really believe history has accidents, in general; there were people behind every decision in the Reformation, and if sources are extant I’d be interested to see their reasoning for agreeing with Luther on half of the Bible and disagreeing on the other half.

You’d need to talk to a historian or scholar of the canon to get the details on how the sausage was made.  I do know the KJV originally had the deuterocanon but the Long Parliament under Cromwell ditched it as too Romish. (Imagine Obama signing an executive order banishing Hebrews and 2 Chronicles from the Bible and you get the hang of how weird this is.) Why Luther was heeded on the OT and ignored on the NT is something I don’t know.  The Jerome Commentary may have some info on the formation of the canon in Protestantism.