Metrication in the United States is the process of introducing the International System of Units to replace obsolete, outdated measurement units used in the United States. The modernized metric system is known as le Système International d’unités (the International System of Units) with the international abbreviation SI.
We here in the United States should change how we measure for many reasons, but international trade is the most obvious reason that should inspire Americans to adopt the same system of measurements all other people use around the world. It sure would create a lot of jobs. Other nations would be more inclined to trade with us. The United States does not actually have a measurement system yet (if one defines a system as a coherent set of inter-related parts).
We could avoid costly disasters like that embarrassment in 1999. The use of two different systems was the root cause in the loss of the $125 million Mars Climate Orbiter. NASA specified metric units in the contract. NASA and other organizations worked in metric units, but one subcontractor, Lockheed Martin, provided thruster performance data to the team in pound force seconds instead of newton seconds. The spacecraft was intended to orbit Mars at about 150 kilometers altitude, but the incorrect data meant that it probably descended instead to about 57 kilometers, burning up in the thin Martian atmosphere.
American scientists use SI because it is so much easier: A liter of water weighs one kilogram, so one cubic meter (1,000 liters) of water weighs 1,000 kilograms, which is one metric ton.
Gallons, pounds, feet, hkwe, awettha and htwa do not share such comprehensive, convenient interrelationships with each other.
Your fingernails grow at the rate of about one nanometer per second. The diameter of our galaxy is one zettameter. It is comparatively cumbersome measuring such small and large things with outdated, obsolete measures like the Burmese Htwa and Awettha or the American inch / pound / gallon collection of random measures with absolutely no inter-relationship.
Some argue that the cost-benefit ratio of adopting a United States National Metrication Policy would preclude its worthiness, but in the grand scheme of things, stubbornly clinging to a clumsy and outdated proprietary non-system is even more costly (and embarrassing).
On 28 July, the Metric Act of 1866 becomes law and legalizes the use of the metric system for weights and measures in the United States. The Metric Act of 1866 was originally introduced as H.R. 596 in the 39th Congress. The House passes it on 17 May 1866 CE; the Senate passes it on 27 July 1866 CE; President Andrew Johnson signs the Metric Act the next day:
“. . . it shall be lawful throughout the United States of America to employ the weights and measures of the metric system; and no contract or dealing, or pleading in any court, shall be deemed invalid or liable to objection because the weights or measures expressed or referred to therein are weights or measures of the metric system.”