At age twenty-one, after finishing his apprenticeship as a harnessmaker, Stephen Harkness moved to Bellevue, Ohio with his paternal uncle Lamon G. Harkness.
Stephen worked for a time in harnessmaking but in 1855, he set up a distillery in Monroeville, Ohio and it became successful.

In 1864 Stephen Harkness formed a partnership with Wm.
Halsey Doan to provide crude oil to refineries.
He became quite wealthy through the profits from this industry.

In 1866, he sold his Monroeville businesses and moved to Millionaires Row in  Cleveland.
 He organized The Euclid Avenue National Bank and was president of Belt Mining Company.

Harkness invested heavily with his younger stepbrother Henry Flagler and  John D. Rockefeller in Rockefeller, Andrews & Flagler, the corporate forerunner to Standard Oil.
Harkness became its second largest shareholder; the company's success made him enormously wealthy.
 Although Harkness was a silent partner, he was a member of Standard Oil's Board of Directors until his death in 1888.

Harkness was active in the development of Cleveland, Ohio.
He collaborated with Charles F. Brush and Rockefeller to build the Cleveland Arcade, one of the first enclosed shopping malls in the United States, modeled after the Galleria Vittorio Emanuele II in Milan, Italy.
At age twenty-one, after finishing his apprenticeship as a harnessmaker, Stephen Harkness moved to Bellevue, Ohio with his paternal uncle Lamon G. Harkness. Stephen worked for a time in harnessmaking but in 1855, he set up a distillery in Monroeville, Ohio and it became successful.
In 1864 Stephen Harkness formed a partnership with Wm. Halsey Doan to provide crude oil to refineries. He became quite wealthy through the profits from this industry.
In 1866, he sold his Monroeville businesses and moved to Millionaires Row in  Cleveland.  He organized The Euclid Avenue National Bank and was president of Belt Mining Company.
Harkness invested heavily with his younger stepbrother Henry Flagler and  John D. Rockefeller in Rockefeller, Andrews & Flagler, the corporate forerunner to Standard Oil. Harkness became its second largest shareholder; the company's success made him enormously wealthy.  Although Harkness was a silent partner, he was a member of Standard Oil's Board of Directors until his death in 1888.
Harkness was active in the development of Cleveland, Ohio. He collaborated with Charles F. Brush and Rockefeller to build the Cleveland Arcade, one of the first enclosed shopping malls in the United States, modeled after the Galleria Vittorio Emanuele II in Milan, Italy.
Stephen V. Harkness