Chapter 5 describes the two most significant events of Rockefeller’s young life: his aggressive entry into the oil-refining business and his marriage to Laura Celestia (“Cettie”) Spelman, both of which occurred before the end of the Civil War.

In 1859, Edwin Drake’s oil strike at Titusville, Pennsylvania, sets off “pandemonium” in the region (76). Through Maurice Clark, Rockefeller meets Samuel Andrews, a scientific pioneer in the refinement of crude oil into kerosene, which Rockefeller immediately recognizes as having immense commercial possibilities as an illuminant. Rockefeller enters an oil-refining partnership with Andrews, Clark, and Clark’s two brothers, James and Richard. Rockefeller begins to immerse himself in the oil-refining side of the business, traveling to the Oil Regions of nearby northwestern Pennsylvania and learning everything he can about production. A second oil strike at Pithole Creek in January 1865 proves that the crude oil will keep flowing for the foreseeable future. Nonetheless, Maurice Clark is more skeptical of oil’s future, so Rockefeller buys out the Clark brothers at auction for $72,500.

Finally, Rockefeller cements his personal happiness by marrying Cettie Spelman, a like-minded young woman of impressive intellectual range. Cettie shared her parents’ (and Rockefeller’s) staunch support for temperance and abolitionism.