Q: I have a collection of these books that were my grandparents.  There is an inscription that says Frank Wright Hamline University December 1907, so I know that the books are at least that old, but know little more as there is no publication date.  My guess is Hamline used them as textbooks maybe?

A: This set of 39 books was published by Altemus between 1899 and 1933. The books originally had dust jackets and some were sold in large box sets. There are a number of different formats and they are well described on the website page noted below.

The Shakespeare Play books are among the most commonly found Altemus publications. They generally do not sell or, if they do, for a couple of dollars each.
See: Shakespeare’s Plays