Here's the clue:
McClellan eventually concentrated his cavalry into a single division before Antietam, and placed it under Brigadier General Alfred Pleasanton, a West Pointer of the class of 1844 with service in the 2nd Dragoons under Zachary Taylor in Mexico.
In honor of international book week, grab the book closet to you, turn to page 52, and post the 5th complete sentence as your status. Please don't mention the title, and post the rules as part of your status. Have fun!
If you can name the book that the above sentence comes from, post your guess as a comment to this blog (not on my Facebook status). The first one to get it right will get the prize.
Hint: It's one of the books that's visible in the above photo. (The name of the book can be read in the photo.)