In the late 19th century John Rockefeller used his quick wits and leadership skills to build an impressive oil refinery in Cleveland. In the early days of the oil industry technology was inefficient and bankruptcies were everywhere, but John optimized the refining process successfully. Over time, he bought out competitors until he had total control over the oil industry in Cleveland through his company: Standard Oil of Ohio.
In the decades afterwards Rockefeller purchased refineries across America and even negotiated backroom deals with the big railroad tycoons. At its peak Standard Oil was worth up to $1,000,000,000,000 (one trillion dollars) in today's money, with Rockefeller controlling over 90% of the oil industry in America.
Of course, eventually new oil deposits were uncovered in Asia and Russia, challenging Rockefeller's monopoly. Back at home concerned businessmen funded waves of media opposition to Standard Oil, which was eventually broken up in 1911. The numerous companies created during this split would eventually merge back together, bringing huge profits to Rockefeller in his final years.
Upon his death, Rockefeller's net worth was an estimated $400 billion in today's dollars, making him the wealthiest businessman to have ever lived by a wide margin.
Under the kind patronage of Nagabhushanam Peddi, Dan Supernault, Samuel Patterson, James Gallagher, Brett Gmoser & Roman Badalyan.