The U.S. is one of the only three countries in the world that have not officially adopted the metric system, along with Myanmar and Liberia. The metric system is a decimal-based system of measurement that uses units such as meters, kilograms, and liters. It is widely used in science, medicine, and international trade. So why does the U.S. still cling to its customary system of inches, pounds, and gallons?
One popular explanation is that the U.S. missed its chance to go metric because of a ship hijacked by pirates in 1793. The ship was supposedly carrying a meter and a kilogram, the standards of the metric system, to Thomas Jefferson, who was the secretary of state and a supporter of the system. However, this story is false and based on a misunderstanding of history.
According to David Clark, a historian of science and technology at the National Institute of Standards and Technology, “The story of the pirates is a myth that has been repeated for over a century, but it has no basis in fact. The ship that was captured by the French privateer was not carrying the meter and the kilogram, but a set of brass weights and measures that were intended to calibrate the U.S. system with the French one.”
In fact, Jefferson had already proposed a decimal-based system of measurement for the U.S. in 1790, but it was not based on the metric system and was rejected by Congress. Jefferson wanted to create a uniquely American system that was based on natural units, such as the length of a pendulum or the weight of a grain of wheat. Keith Martin, a curator at the Smithsonian National Museum of American History, explains that “Jefferson was a strong advocate of a decimal system, but he did not want to adopt the French metric system. He wanted to create a uniquely American system that was based on natural units, such as the length of a pendulum or the weight of a grain of wheat.”
The U.S. did not officially recognize the metric system until 1875, when it signed the Treaty of the Meter, which established the International Bureau of Weights and Measures and recognized the metric system as the international standard. However, the U.S. did not make any serious attempt to convert to the metric system until 1975, when it passed the Metric Conversion Act, which declared the metric system as the preferred system of weights and measures and created the U.S. Metric Board to coordinate the voluntary conversion.
However, the conversion was met with resistance from many Americans, who were used to the customary system and found it more intuitive and practical. There were also economic and political costs associated with changing the system, such as retooling industries, updating laws and regulations, and educating the public. John Bemelmans Marciano, the author of Whatever Happened to the Metric System?, argues that “The U.S. has a long history of resistance to the metric system, which is often seen as foreign, elitist, or unnecessary. Many Americans are used to the customary system and find it more intuitive and practical. There are also economic and political costs associated with changing the system, such as retooling industries, updating laws and regulations, and educating the public.”
On the other hand, some advocates of the metric system claim that it is not only a scientific standard, but also a symbol of global cooperation and unity. It is a common language that facilitates trade, communication, and innovation across borders and cultures. It also promotes accuracy, efficiency, and rationality in measurement and calculation. Martin Milton, the director of the International Bureau of Weights and Measures, states that “The metric system is not only a scientific standard, but also a symbol of global cooperation and unity. It is a common language that facilitates trade, communication, and innovation across borders and cultures. It also promotes accuracy, efficiency, and rationality in measurement and calculation.”
The U.S. is not completely isolated from the metric system. In fact, it uses the metric system in many areas, such as science, medicine, military, and sports. The U.S. is also legally metric, since the customary units are defined in terms of the metric units. However, the U.S. is still far from being fully metric, and there is no clear indication that it will change anytime soon. Elizabeth Gentry, the metric coordinator at the National Institute of Standards and Technology, concludes that “The U.S. is not completely isolated from the metric system. In fact, it uses the metric system in many areas, such as science, medicine, military, and sports. The U.S. is also legally metric, since the customary units are defined in terms of the metric units. However, the U.S. is still far from being fully metric, and there is no clear indication that it will change anytime soon.”
Relevant articles:
– Are Pirates Who Hijacked Measuring Tools Intended for Thomas Jefferson the Reason US Isn’t Metric?, Snopes.com, Aug 6, 2023
– Why Doesn’t the U.S. Use the Metric System?, Britannica, Nov 10, 2023
– Why America won’t go metric, CNN Politics, Nov 12, 2023
– The Metric System: A Tale of Failed Adoption in the United States, The New York Times, Nov 11, 2023