[1] He apprenticed himself to a physician and then took a medical degree from the Philadelphia College of Medicine and the University of Pennsylvania.

Hewston established a new medical practice upon his arrival, supplementing his income by lecturing at the Toland College of Medicine (later known as University of California, San Francisco).

His skill at lecturing brought him to the attention of the People's Party, which nominated him for San Francisco Board of Supervisors in 1873.

His final political activity was as chair of the Anti-Monopoly Party, which sought to stop the transfer of federal lands for the railroads.

Hewston then returned to the lecture circuit and travelled along the East Coast, collecting many books along the way.