The Mendenhall Order marked a decision to change the USA's weights and measures from the customary system based on that of England to the metric system.
It was issued on April 5, 1893 by Thomas Corwin Mendenhall, superintendent of the U.S. Coast and Geodetic Survey, with the approval of the United States Secretary of the Treasury, John Griffin Carlisle. The order was issued as the Survey's Bulletin No. 26 - Fundamental Standards of Length and Mass.
See also
Metric system in the United States
