John D Rockefeller (peak year-1911)
Widely regarded as the wealthiest American of all the time and the wealthiest person in modern history.
John D Rockefeller had a peak net worth of about three hundred sixty-seven billion dollars in today’s money, he made his money in oil refining in the standard oil trust that he founded controlled 90% of the supply of oil in the United States.
He revolutionized the American oil industry through his strategies of integration transportation and marketing, and his company became so big than in 1911. The supreme court ruled that it was in violation of antitrust laws and split it into 34 different companies.
Rockefeller received proportionate shares in these new companies in over the next 10 years; this proved immensely profitable as their net worth rose fivefold.
He used his unprecedented wealth to pioneer the modern system of philanthropy, creating a foundation that even today have a significant impact on medical education and scientific research.