Notes:
Date and information from American Comic Strip Collections 1884-1939 by Dennis Gifford.
Year of release probably confirmed from the Official Gazette of the United States Patent Office. Volume 488, March 1938 (March 1), page 21. Listings of published trademarks. Trademark for Feature Books (not Feature Book), trademark serial number 400,983, for David McKay Company of Philadelphia, Pennsylvania. The word "books" disclaimed from apart from the mark, for periodical publication. Claimed by David McKay Company to have been used since November 17, 1936.