

In 1893 the Cassell Publishing House was reorganized. Apparently its previous manager Oscar Dunham had absconded with $180,000 and financially Cassell was in a desperate situation. A new Cassell Publishing Company was organized in New York with William Mershon as president and manager. Prior to this Mershon had been in charge of his own bookbinding, electrotyping, and printing establishment. in Rahway , NJ.
In 1897 Mershon left Cassell to start his own publishing company. In 1905 the name of the firm was changed to Stitt. Apparently the new company run by William Stitt was not successful and the company returned to the Mershon imprint in 1906.
Apparently He was in business until October,1906 at which time his publishing business were sold to Chatterton- Peck. Charles Peck had been a long time employee of The Mershon Company.
For more details see John Dizer: Tom Swift. the Bobbsey Twins and Other Heroes of American Juvenile Literature. The Edward Mellen Press. 1997

Here are two sample ads from a book sales service:
Captain Bailey Heir
Henty, G. A.
Mershon, 1900. Hard cover. Book Condition: Good. Good. No dust jacket as issued.
By England's Aid Or The Freeing Of The Netherlands 1585-1604
Henty, G.A.
Mershon Company. Hardback. No Dustjacket, probably as issued.
It amazes me that without knowledge and without doing the research that some dealers assume jacketless books are the norm- when quite the opposite is the case. This entry shows a couple of jacketed Mershon books from the first decade of the 20th century.