Tarbell published a pointed character study of John D. Rockefeller, extending her scrutiny of industrial power beyond the Standard Oil series.
In July 1907, Ida Tarbell published "Rockefeller: A Character Sketch," a pointed personal and psychological profile of John D. Rockefeller that extended her earlier institutional critique of Standard Oil into an examination of the man himself. Where her earlier work had focused on corporate practices and business history, this piece turned attention to Rockefeller's personality, motivations, and public persona.
The sketch was notable for its unflinching tone, portraying Rockefeller as a man whose immense wealth and religious piety existed in uncomfortable tension with the ruthless business practices that built his fortune. It contributed to the broader public perception of Rockefeller as an emblem of the excesses of Gilded Age capitalism, even as he was simultaneously engaged in high-profile philanthropy to rehabilitate his public image.
This publication demonstrated Tarbell's range beyond straightforward investigative reporting into more literary and biographical forms of muckraking journalism. It reinforced her standing as the nation's foremost chronicler of Rockefeller and Standard Oil, and it remains an important primary source for historians studying how public opinion of American industrial titans was shaped in the early twentieth century.