| Year |
Event |
| 1670 |
Records of a first Metric System by Gabriel Mouton, a French vicar |
| 1795 |
Republic of France adopts the first basic Metric System proposed by the French Academy of Sciences |
| 1820 |
Belgium, Luxembourg and the Netherlands are the first of a growing number of other countries to switch to the Metric System |
| 1866 |
Congress legalizes the use of the Metric System in the US |
| 1893 |
The US adopts metric units as fundamental standards for length and mass |
| 1902 |
Congressional legislation requiring the federal government to use SI exclusively was defeated by a single vote |
| 1959 |
English units are defined in terms of metric units |
| 1970 |
Practically all the world has adopted the Metric System - the US, Liberia and Burma remain the only countries still using the English Imperial units |
| 1975 |
Metric Conversion Act (Public Law 94-168) passed by Congress |
| 2001 |
The US still have no definitve plan in sight for an adoption of the Metric System |