What Are the Most Famous Monopolies?

To date, the most famous United States monopolies, known largely for their historical significance, are Andrew Carnegie’s Steel Company (now U.S. Steel), John D. Rockefeller’s Standard Oil Company, and the American Tobacco Company.

American monopolies date back to colonial administrators who awarded large companies exclusive contracts to help build the New World. From the late 19th to the early 20th century, the three organizations mentioned above maintained singular control over the supply of their respective commodities. Without free-market competition, these companies could effectively keep the price for steel, oil, and tobacco high.


A History Of U.S. Monopolies

Understanding the Most Famous Monopolies

Government regulation of early American monopolies was initially absent. However, the creation of antitrust regulation in the United States, in the form of the 1890 Sherman Antitrust Act, led to the eventual dismantling and restructuring of Standard Oil and American Tobacco by 1911. Like many antitrust cases brought against companies even today, it took several years for these first cases to navigate through the court system.

Key Takeaways

  • Until around 100 years ago, a single large company could completely control some major U.S. industries, like steel and oil. 
  • Passage of the Sherman Anti-Trust Act in 1890 eventually saw major U.S. monopolies break up.
  • A type of limited monopoly that still exists worldwide can be found in the form of nationalized major assets.

Unlike Standard Oil and American Tobacco, U.S. Steel was challenged, but not found to be the sole supplier of steel to the U.S. market. However, it continued to possess considerable market share for many years. In 2019, U.S. Steel was the 27th-largest producer of steel in the world, according to the World Steel Association.

More Modern Times

A more recent monopoly to have experienced the same fate as Standard Oil and American Tobacco is the American Telephone and Telegraph Company (AT&T).

In 1982, AT&T was found to be in violation of U.S. antitrust law while acting as the sole supplier of telephone services to the country. As a result, it was forced to split into seven subsidiaries, known as Baby Bells.


A good example of a near-monopoly from very recent history is the De Beers Group, the best-known diamond mining, production, and retail company in the world. De Beers was close to a true monopoly for almost a century, but due to a variety of market and regulatory factors, it has seen its market share go from over 80% in the late 1980s to around 35% in 2019.

While several U.S. companies in sectors like technology, consumer products, and food and beverage manufacturing have been accused of being monopolies in the media and some in courts, they have rarely been proven so.

The Role of Nationalization

Most monopolies that exist today do not necessarily dominate an entire global industry. Rather, they control major assets in one country or region. This process is called nationalization, which occurs most often in the energy, transportation, and banking sectors.

The largest such example of a nationalized major asset is Saudi Arabia's Saudi Aramco, the nation's state-owned oil and natural gas company. It is arguably the single most valuable company in the world at $1.7 trillion as of its late 2019 IPO valuation.

The Bottom Line

For everything, there is a season, even for monopolies. Monopolies often can help a country or region build or shore up its infrastructure quickly, efficiently, and effectively. But when any company becomes too dominant, leaving little room for competition, service, quality, and consumer wallets can suffer. That's where antitrust laws come in.

Article Sources

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  2. World Steel Association. "Top Steel-Producing Companies 2019." Accessed Oct. 19, 2020.

  3. The Minnesota Journal of Law, Science and Technology. "Whatever Happened to the Baby Bells? Internationalization and De-internationalization in the Telecommunications Industry," Page 151. Accessed Oct. 19, 2020.

  4. Paul Zimnisky. "A Brief History of De Beers." Accessed Oct. 19, 2020.

  5. Saudi Aramco. "Our History." Accessed Oct. 19, 2020.

  6. Saudi Aramco. "Saudi Aramco 2019 Annual Report." Accessed Oct. 19, 2020.