This firm published the paperback Log Cabin Series. I believe that this series was published in the early 1920's and consisted of more than fifty books.

Note that the Cleopatra book states Log Cabin Library on the title page. It is unclear to me what distinguishes the "Series" from the "Library".

As of this time the following Abbott books are known to be part of this list:

Nero
Julius Caesar
Josephine
Cleopatra

Josephine mistakenly gives the author as Jacob not John S. C. Abbott.