Thomas Jefferson

• In 1789, Thomas Jefferson, then the U.S. secretary of state, developed a system of measures quite similar to what would become the metric system. Congress, however, never adopted it into law as the nation's only system of measurement.
  
  

Current Legal Status

• According to the U.S. Metric Association, the Metric Conversion Act (passed in 1975; amended in 1988) states that the metric system is the nation's preferred measurement system and that the government encourages its use.
  
  

Consumer Resistance

• Despite the metric system's simplicity and widespread use around the world, U.S. consumers have resisted a wholesale conversion away from the foot, mile, pound and other non-metric measurements.
  
  

Product Labeling

• In keeping with consumers' preference for familiar measurements, most consumer products created today are labeled with the non-metric measurement followed by the metric measurement in parentheses.
  
  

Fields Where Metric Measures Are Standard

• In certain lines of work in the U.S., the use of metric measurements is standard. The fields of science, engineering, manufacturing and international trade depend almost entirely on the metric system.