How was rockefeller able to build his monopoly across the oil industry

Buying rival refineries

Explanation: American industrialist John D. Rockefeller was born July 8, 1839, in Richford, New York. He built his first oil refinery near Cleveland and in 1870 incorporated the Standard Oil Company. By 1882 he had a near-monopoly of the oil business in the U.S., but his business practices led to the passing of antitrust laws.

Standard Oil gained a monopoly in the oil industry by buying rival refineries and developing companies for distributing and marketing its products around the globe.

i also think he is correct. i believe they came to washington to protest their rights.