Charles and David Koch, commonly known as the Koch brothers, inherited their father's fortune from his business, Rock Island Oil and Refining Company, and then expanded upon the business and formed Koch Industries, Inc., a company that earned an estimated $100 billion in revenue in 2009. The brothers, who have an estimated net worth of about $20 billion each as of 2015, use their wealth to lobby for laws, particularly relaxed environmental regulations, that further increase their company's earnings.
Fred Koch, the Koch brothers' father, was an oil engineer who made his fortune by creating a process called thermal cracking, which transforms petroleum into gasoline and lighter oils. The Koch Brothers, along with their two other brothers, inherited their father's fortune. They bought out their brothers' share of their father's company in 1983.
Koch Industries is currently an oil conglomerate that trades oil products and uses them to create products such as fertilizer, active wear and smartphone components. The Koch brothers continue to aggressively grow the company, pushing relaxed environmental regulations and funding Republican candidates. The brothers were particularly instrumental in the founding of the Tea Party. In 2014, a University of Amherst study concluded that Koch Industries was one of the top three polluters of the environment.