Mary Wright Plummer was born in Richmond, Indiana to Quaker parents and attended the Friends Academy.

At Columbia University she entered the first class taught by Melvil Dewey at the School of Library Economy in January 1887.

She completed the program in 1888 and served as a cataloger for two years at the Saint Louis Public Library.

[2] Her publications include a collection of poetry (e.g., Verses), several children's books (e.g., Stories from the Chronicle of the Cid), and books on the profession of librarianship (e.g., Hints to Small Libraries and Training for Librarianship).

Plummer held leadership roles in the library profession at a time when it was unusual for women to lead.