Q: What is the origin and reason why the U.S. uses the customary measuring system while the majority of the world uses the metric system?
—Kathy McDonough, Peachtree Corners
A: The United States' customary, or standard, system developed from the British imperial system, while the metric system originated in France in the 18th century.
There have been official investigations into the pros and cons of both systems and numerous movements for the United States to convert, dating to the early days of the country.
Thomas Jefferson investigated the French metric system and invented another decimal-based system, but Americans were left “with a version of the traditional English weights and measures,” retired University of North Carolina math professor Russ Rowlett wrote.
A thorough 1821 report by then-Secretary of State John Quincy Adams didn’t recommend the metric system, which was struggling to take hold in France.
“A History of the Metric System Controversy in the United States,” a 1971 report for Congress, stated the country was too busy with expansion and industrialization in the mid-1800s to be concerned with the metric system, which was being adopted by other countries.
President Andrew Johnson, in 1866, signed a law for the U.S. “to employ the weights and measures of the metric system in all contracts, dealings or court proceedings,” but that “couldn’t kill the U.S. customary system,” CNBC.com wrote.
A movement to convert to the metric system in the 1970s-80s, including 1975’s Metric Conversion Act, “lost momentum,” the U.S. Metric Association states on its website, but the country now uses a mix of both systems.
Experts agree it would cost billions of dollars for the United States to fully convert to the metric system.
Andy Johnston with Fast Copy News Service wrote this column. Do you have a question? We’ll try to get the answer. Call 404-222-2002 or email q&a@ajc.com (include name, phone and city).
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