Summarize what made John D. Rockefeller such a successful businessman?

United States industrialist who made fortune in the oil business and gave half of it away (1839 - 1937)

John D. Rockefeller was an American industrialist and magnate born in July 8th in Richford, New York. In his early years, he built his first oil refinery in Cleveland and later, in 1870, incorporated the Standard Oil Company. By the year 1882, he had already built a near-monopoly of the oil business, which made him the richest person in modern history. Later in life, he devoted himself to philathropy up to his death in 1937.