Metric Conversion Act signed by U.S. President Gerald Ford.
The act made the metric system the preferred system of weights and measures in the United States. Today, the metric system is predominantly only used by scientists and academics in the U.S. Common people tend to follow the customary units that were developed before American Independence. The U.S. is 1 of 3 countries in the world that do not use the metric system. Liberia and Myanmar are the other two.