Altemus published ten Wee Folks’ Library Sets. Each set consisted of four Wee Books’ titles in a colorfully illustrated box for $2.25 each. The first six sets were published in 1921. The next four in about 1923.

There were sets that did not conform to the catalogue listings. Because these boxed sets are so rare, a comprehensive listing of the variants is impossible. Here is a recently discovered example. The books in the set below have the 1928-1929 variant cover.
Four books are within the box:
1. Old Red Reynard, the Fox
2. Grunty Grunts and Smiley Smile Indoors
3. Hootie Toots Hollow Tree
4. The Robber Kitten

Of interest is that Hootie Toots was published in 1925 -after the ten boxed sets were produced. Thus there must have been other boxed sets not described.

For more information see: http://www.henryaltemus.com/wee_books/index.htm