Cleveland was the first center of his oil empire

One of the interesting facts about John Davison Rockefeller is that Cleveland was the first center of his oil empire. In 1866, John's brother, William Rockefeller Jr., built another refinery in Cleveland and welcomed John into the company. In 1867, Henry Morrison Flagler joined the firm, and the name Rockefeller, Andrews & Flagler was born. By 1868, with Rockefeller continuing to borrow and reinvest profits, limit costs, and use refinery waste, the corporation controlled two Cleveland refineries and a marketing subsidiary in New York, and it was the world's largest oil refinery. The Standard Oil Company was founded by Rockefeller, Andrews, and Flagler.

By the end of the American Civil War, Cleveland had become one of the country's five major refining centers (besides Pittsburgh, Pennsylvania, New York, and the region in northwestern Pennsylvania where most of the oil originated). By 1869, there was three times the kerosene refining capacity required to serve the market, and this capacity remained excessive for many years.

Rockefeller dissolved the partnership of Rockefeller, Andrews, and Flagler on January 10, 1870, establishing Standard Oil of Ohio. Rockefeller quickly built the company to become the most successful refiner in Ohio by applying his work ethic and efficiency. Similarly, it grew to become one of the country's leading shippers of oil and kerosene. The railroads competed fiercely for traffic, and in an attempt to form a cartel to control freight prices, they founded the South Improvement Company, which offered special deals to bulk customers such as Standard Oil outside of the major oil centers. As a high-volume shipper, the cartel provided special treatment, including not just hefty discounts/rebates of up to 50% on their goods, but also rebates for the shipment of competitor items.