The series is estimated to have started around 1933 from a study of copyright data from the U.S. Copyright Office (http://www.copyright.gov/records/).
This is a weekly series that took the proof pages that the syndicate would send to newspapers, copy and reduce them, and then bind them into the weekly publication that was sent to the U.S. Copyright Office to obtain copyright on that material. This series contains mostly syndicated columns, puzzles, and factoids to be used for newspaper publication. The series also contains some comic and editorial cartoon material, probably meant for weekly local newspapers instead of daily newspapers.
Probably intended for the U.S. Copyright Office, these copyright books periodically show up for sale, most likely either discarded material from the U.S. Copyright Office or, most likely, through limited subscription and local New York city newsstand sales.
Not to be confused with King Features Illustrated Weekly, a pre-packaged magazine which mostly focused on comic and other pictorial material, and was meant to bound within newspapers.
It is possible this publication is no longer produced in paper form but instead submitted electronically to the U.S. Copyright Office.