Mershon published its Rollo's in several different series. The Wideawake Series and the Rollo's Tour in Europe (10 titles in five volumes) are the most well known. The ten Rollo books also appeared in the post-1902 Regal Series, Standard Series and Standard Sixteen Mos. Series. The names of the other series are as of yet unknown.

Dating the Mershon books exactly can be difficult. These books can be divided into 1897-Early 1902 and later 1902-1906. The 1897-early 1902 books' imprints only have New York. The later books also list the Rahway, N.J. location.

Standard Series 1900                             Standard Sixteen Mos Series 1902

Unknown Series - Pre-1902

Unknown Series Pre-1902

Unknown Series Pre-1902

Wideawake Series Post-1902

Rollo's Tour in Europe Series Post-1902

Regal Series

Unknown Series Post-1902