John Davidson Rockefeller was born July 9, 1839 in Richford, New York. Rockefeller attended Cleveland Central High School as a young boy. He was determined to work for himself so he saved all his money. His first business was with a young Englishman named Maurice Clark. The business was called Clark & Rockefeller Produce and Commission and it sold farm supplies and household goods. This company wasn't good enough for Rockefeller so he sold it.
 John Rockefeller made a company with Samuel Andrews called Standard Oil. The cost of shipping oil was very high so he made a deal with the Railway Company and it lowered the prices from .40 to .35 to Cleveland refineries and from $2.00 to $1.30 to New York refineries. The sales increased dramatically and this was the beginning of his monopoly.
In one year four of his competitors were out of business and he had monopolized refining in Cleveland. By 1890 he could fix his own prices because he had no competitors. In 1896 he was worth about $200 million.
President Theodore Roosevelt attempted to use the Sherman Anti-Trust Act to deal with Rockefeller’s monopoly over the oil industry.  In 1901 Rockefeller’s fortune had reached around $900,000,000 probably making him the richest man at the time. It wasn't until 1911 that the Supreme Court had destroyed the Standard Oil monopoly.
Over the next few years John D. Rockefeller gave over $500 million in aid and medical research.