Mr. Savino reviewed the AKC stud book records they track the ancestry of every dog and bitch that's been party to a registered blessed event since the late 19th century then checked earlier stud books from the National Kennel Club (available only on microfilm) as well as a bound catalog from the 1878 Westminster competition.
WSJ: A Library With a Pedigree | American Kennel Club Research Library | By Joanne Kaufman