CNN
 — 

At first, it was the rare binding that caught the eye of Danielle Linn, a senior book specialist with Fleischer’s Auctions.

While cataloging items once owned by the Union Army General, William Tecumseh Sherman, she came across a copy of a memoir written by Ulysses S. Grant. The book had been made with rare “tree calf” binding – leather chemically treated to create the likeness of a tree on the cover.

Linn set it aside, but later picked it up to check the publication date. The specialist opened the back cover accidentally, she said, and that’s where she found Sherman’s handwriting. Not only was it…