Exxon Mobil Corporation

John D. Rockefeller founded Standard Oil of Ohio in 1870 and proceeded to build the most dominant corporate monopoly in American history. Through aggressive pricing, secret railroad rebates, and systematic acquisition of competitors, Standard Oil controlled 90% of U.S. oil refining by 1879. Rockefeller became the wealthiest person in American history — his fortune, adjusted for inflation, was larger than those of Bill Gates and Jeff Bezos combined.

The U.S. Supreme Court ruled in 1911 that Standard Oil violated the Sherman Antitrust Act and ordered it broken into 34 separate companies. Among the successor companies were Standard Oil of New Jersey — which became Exxon — and Standard Oil of New York — which became Mobil. The breakup was intended to reduce Rockefeller's power. Instead, the separate companies' combined value quickly exceeded that of Standard Oil as a whole, making Rockefeller even wealthier.

On March 24, 1989, the Exxon Valdez oil tanker ran aground on Bligh Reef in Alaska's Prince William Sound, spilling 11 million gallons of crude oil in one of the worst environmental disasters in U.S. history. Exxon's response was widely criticised as slow and inadequate. The company was eventually ordered to pay $5 billion in punitive damages — later reduced to $507.5 million by the Supreme Court after 19 years of litigation.

Exxon acquired Mobil in 1999 for $81 billion — at the time, the largest corporate merger in history. The two companies, which had been separated by antitrust regulators 88 years earlier, were reunited as ExxonMobil. The merger created the world's largest publicly traded company by market capitalisation.

A small activist hedge fund called Engine No. 1, with less than 0.02% of ExxonMobil's shares, successfully elected three directors to ExxonMobil's board in 2021 by convincing large institutional investors that ExxonMobil's resistance to the energy transition was destroying shareholder value. It was one of the most consequential shareholder activism campaigns in corporate history. ExxonMobil subsequently announced significant investments in carbon capture and low-carbon energy — while simultaneously expanding oil production.