The Pomona Public Library began in 1887, and was originally located in a single room of the Ruth Block Building (pictured above) located at Third and Main. The Library was open for three hours, two afternoons per week, and the collection consisted of 400 books.

The Library would subsequently move to three rooms in the Union Block Building, on Second and Thomas Streets in 1892. It remained at this location until the Carnegie Building was completed in 1903.