I have a lot of old books, most around the turn of the 20th century. Without poking through every single one of them, the one that came to mind is this bound 1894 volume of the annual report of the State Board of Agriculture of the State of Michigan:
This might seem a dry read, but it contains a long chapter (actually departmental report), "The Birds of Michigan" by A. J. Cook, the first comprehensive annotated checklist of the state’s birds. I have referenced it a lot. The first really great Michigan bird book followed in 1912, by Walter Barrows. There are actually a lot of copies of this floating around (in better shape), but I treasure my stained and spinally-challenged copy, as it was given to me by my late brother.
As did Aydin at Snail’s Tales, I’ll include an old scientific paper. I have a boatload of those, too, but my favorite bunch is the complete run (1897-1904) of the short-lived Bulletin of the Michigan Ornithological Club.
Every person with an interest in natural history should try to find similar books and journals for their area. Nothing can give you a deeper sense of place, or a clearer appreciation for what we have lost.