John Hay wrote the Bixby letter

[Steve]

A couple of things about that New York Times article -

Although it toots it own horn, I believe the first claim in print that Hay was the author of the Bixby Letter was in 1922, a full decade before the 1933 editorial.

The new study on the Bixby Letter hasn't even been published yet. On the website of Digital Scholarship in the Humanities, the journal the paper was submitted to, the April 2018 issue is next.

https://academic.oup.com/dsh/issue/32/suppl_2