Mosby's farewell speech to his Raiders, 4/21/1865

I found this letter, embedded in a Confederate scrapbook, in 2009, while researching Jonathan Sturges (see page on Sturges elsewhere on this site) at his country home in Fairfield, CT. A successful merchant and railroad president, as well as an enlightened and generous patron of 1800s American artists including Thomas Cole, Asher B. Durand, and William Sidney Mount, Sturges was a patriot and ardent Unionist. I found the book late one night (or early one morning depending on your interpretation) while rummaging through the lower cabinet of a secretary in Sturges's library. Jumbled together with documents including an 1850s bill of sale from Tiffany, Young, & Co, cancelled checks from a century later, and old newspapers, my eye fell on an ornate Victorian binding. I pulled out the book and opened it, to find it was a typical scrapbook with articles cut from newspapers and periodical. EXCEPT!!! the newspapers were Confederate, dating to Civil War years. This seemed odd given that Sturges was a founder of the New York Union League Club who helped equip and send out the first black regiment from NYC. He also personally knew Lincoln, Ambrose Burnside, and George McClellan. Puzzlement led to electric shock as a page near the front of the book fell open. On the left-hand side of the page was pasted a letter signed "Jno S. Mosby." I know a modicum of American history, enough to immediately recognize the name--when combined with the inscribed date of April 21, 1865, this document really gave me a jolt. I read the lines quickly and realized that this was Mosby's speech bidding farewell to his famous partisan troops. After doing a web search, I discovered that Mosby's speech is reproduced word for word on the internet, it is that famous. I ascertained that there exists but one period copy in Mosby's hand, owned by the Museum of the Confederacy in Richmond, VA. It turns out that Mosby had multiple copies of the document made out to read to individual groups of men situated in an open field--being outside and in significant numbers, Mosby wouldn't have been able to successfully communicate his moving message that day. Not only are there contemporary copies written by aides, but Mosby himself, later in life, apparently copied the document on demand. Would my discovery prove to be an original, only the 2nd one known? YES!!! It was and became the cover lot in an historical artifacts sale organized by Heritage Auctions and held in Beverly Hills, in February 2010, selling for almost $80,000. I wrote a brief essay describing my find, which was reproduced in the auction catalogue, without giving me credit. Now, how did the book get into this  Union household? Matching article and handwriting comparisons with family letters led to the conclusion that the book entered the Sturges family through the wife of Jonathan Sturges's youngest son, Henry Cady, inheritor of the house. Henry married a Southern girl, Sarah McWhorter, two of whose brothers fought on the Confederate side for Georgia, having grown up in Augusta. The details of how the Mosby letter got to the McWhorter family are unknown.