USA And Metric System

Article I, Section 8 of the U. S. Constitution gives Congress the power to "fix the standard of weights and measures" for the nation. The First Congress, meeting in 1789, took up the question of weights and measures, and had the metric system been available at that time it might have been adopted. What actually happened is that Thomas Jefferson, who was then serving as the first Secretary of State, submitted a report proposing a decimal-based system with a mixture of familiar and unfamiliar names for the units.

Jefferson's system actually resembles the metric system in many ways. Its biggest shortcoming is that Jefferson didn't hit on the idea of using prefixes to create names for multiples of units. Consequently, his system was burdened with a long list of names. For example, he divided his basic distance unit, the foot (it was slightly shorter than the traditional foot) into 10 inches. Each inch was divided into 10 lines, and each line into 10 points. For larger distances, 10 feet equalled a decade, 100 feet was a rood, 1000 feet a furlong, and there were 10 000 feet in a mile (making the Jeffersonian mile about twice as long as the traditional mile). His basic volume unit was the cubic foot, which he proposed to call a bushel (it was about 3/4 the size of a traditional bushel). The basic weight unit was the ounce, defined so that a bushel of water weighed 1000 ounces. (This is very similar to the metric system, in which a liter of water weighs 1000 grams).

Congress gave this plan serious consideration, but because it lacked independent support from other scientists it was easy to criticize. Ultimately, Congress took no action. This left Americans with a version of the traditional English weights and measures, including:

distance measurements identical to those of the 1592 Act of Parliament,
the traditional avoirdupois system of weight measurements,
a system of measurement for dry volumes based on the "Winchester" bushel used in England for wheat and corn since the late Middle Ages, and
a system of measurement for liquid volumes based on the English wine gallon of 1707