The American Racing Manual from 1967 and 1980.
Headquarters: A History of New Market and It's Racing.
The DRF Champions.
The Horse and the Bluegrass Country.
The Life History and Magic of the Horse.
Just Horses: Living With Horses in America
I also picked up a bunch of Kovel's guides, the 1902 Sear's catalog and a bunch of paperbacks. Just thought I would share my day's finds.