W. B. Conkey Company, Chicago. Post-1900
Conkey published Rollo books in a number of series.

Initially the Amaranth Series, University Series and New Ivory Series included all ten Rollo books. By 1904 only Rollo in London was part of these series. All ten titles were published in the Franklin Series of paper books and the Rollo Series. The latter series, the Rollo Series' covers were used by Homewood Publishing Company.

Rollo Series

Rollo Series

Rollo Series

Amaranth Series- early 1900's

Amaranth Series- 1904

University Series (16 mos.)- 1900

University Series- 1904

New Ivory Series- 1904

Unknown Series

Unknown Series

Unknown Series