The Williams-Sonoma Kitchen Library is one of the only series that competes with World War II in length; it is a whopping 44 volumes long.
These books were published throughout the 90's and I believe that these were actually sold at the Williams-Sonoma stores, but I have seen them around in other stores. Given that my closest encounter with gourmet food is watching 'Iron Chef' and arguing with my fiancee over which dish is most unappetizing, these books never really seemed to be something I'd pick up. If you are the cooking type, though, and you've got these, let me know how they are.
I have had someone tell me that "Cuisine Grand-Mere: Traditional French Home Cooking" is not the same size or style as the other books here; but I haven't been able to verify it either way yet. The list that I got off of the Library of Congress site states that this book is a member of this set, but it looks like it was published to be a stand-alone volume; so unless you are a supreme collector and you believe the Library of Congress it looks like this series is 43 volumes.