Standard Oil owned ninety percent of all oil refineries in the United States.
Explanation:
The idea of Rockefeller materialized in 1882, creating the Standard Oil Trust, where companies would operate in a cooperative manner, centralizing all decisions in the main office of the Standard Oil of Ohio, which served as head of the group. This type of organization was so successful that other large companies also began to take the form of trust. In parallel, new state and federal antitrust laws would emerge to avoid such tactics. However, by then, Rockefeller was already the owner of the oil industry in the United States and for now nothing could change that situation.
