The Harvard Classics are more commonly known as "The Five-Foot Shelf", were compiled and edited by Harvard University president Charles Eliot and first published in 1909.
Eliot's goal was that the books provide a liberal education to anyone willing to spend 15 minutes a day reading from the collection.
I wanted some books for the drawing room that looked good, but that would actually be read. I scored a set of first editions on ebay and although I haven't read the complete collection, I am always very interested by what I do read.
A reading guide is available here.