A thought experiment

A lot of people, not just LDS scholars and educators but ordinary members of the Church, are emotionally attached to their ideas about Book of Mormon geography. I empathize because I felt the same way for decades about the Mesoamerican theory.

So here’s a thought experiment to consider.
First, set aside your preconceptions. Thought experiments don’t work if our minds are cluttered. We need to start with a blank slate.
Second, pretend for a moment that Oliver Cowdery and Joseph Smith knew that the Hill Cumorah of Mormon 6:6 was the same hill where Joseph obtained the plates; i.e., the hill in New York near his home. 
Maybe they knew because they had visited Mormon’s records repository in the hill, as they told Brigham Young and others.
Maybe they knew because Moroni told them. 
Or maybe they had a revelation about it. After all, they were both apostles. Joseph was President and Oliver Assistant President of the Church. They didn’t record everything they knew, as we know from Joseph Smith-History, 1:73-4:
 73 Immediately on our coming up out of the water after we had been baptized, we experienced great and glorious blessings from our Heavenly Father. No sooner had I baptized Oliver Cowdery, than the Holy Ghost fell upon him, and he stood up and prophesied many things which should shortly come to pass. And again, so soon as I had been baptized by him, I also had the spirit of prophecy, when, standing up, I prophesied concerning the rise of this Church, and many other things connected with the Church, and this generation of the children of men. We were filled with the Holy Ghost, and rejoiced in the God of our salvation.
 74 Our minds being now enlightened, we began to have the scriptures laid open to our understandings, and the true meaning and intention of their more mysterious passages revealed unto us in a manner which we never could attain to previously, nor ever before had thought of
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Continuing with this thought experiment, if Cumorah is in New York, does the rest of the description in the text fit?
Step 3 in the experiment is to see if you can work it out.
Again, throw out all your preconceptions and re-read the text.
I realize that because of Mesomania it’s nearly impossible to jettison the maps and illustrations you’ve seen your whole life, but try. 
You might be surprised at what you discover.
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The irony of this thought experiment is that it shouldn’t really be an experiment at all. Latter-day Saints believe everything Joseph and Oliver told us except for what they wrote in Letter VII. We write entire books about one-off statements recorded in someone’s journal, such as the “most correct book” comment that wasn’t even a quotation. 
But unlike these one-off statements, Oliver’s letters, including Letter VII, have been republished multiple times. LDS scholars and educators accept everything in them except what they wrote about the Hill Cumorah.
If you know the explanation for that, you’ll figure this out soon enough.
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One stumbling block for some scholars is that Joseph didn’t identify the hill as Cumorah in Joseph Smith-History. There’s a good reason why he might have chosen not to, but the objection assumes Joseph wrote the history in the first place.
He did not.
At most, he read it. We don’t even know if he made corrections to it, but we assume he approved it on some level.
See if you can think of a reason or two he might not have named the hill in that history.

Source: Book of Mormon Concensus