The United States is not among them. Although Thomas Jefferson showed interest in the system when he was Secretary of State in the1790s, nothing has changed. According to Ken Alder, a professor of history at Northwestern University, Americans may just have the idea of standardizing something on a global scale. "When people see it as a global long-distance force that produces unity, I understand that when people hate it, it is completely reasonable to want local control," he told Life Science. "This can also be a stand against super-rationality and France."
In addition, the British industrial revolution began to gain a foothold in the United States in the 1800 s, and most manufacturers used inches, pounds and all other familiar British units to calibrate machines and measure products. As the Encyclopedia Britannica explains, it is laborious and expensive to switch to metric system. Whenever Congress proposes, business owners and citizens will quickly shut it down. Two centuries later, the same problem continues to prevent the United States from adopting the metric system.
This is not to say that we haven't tried. 1975, Congress passed the metric conversion law to encourage enterprises to transition to metric units of measurement. Since it is not mandatory-English units will still be accepted-it has hardly changed the status quo. In the second half of that decade, President Jimmy Carter took the lead in launching a movement to change the miles on road signs into kilometers, but this movement did not last.
Alder pointed out that France was able to implement a new system, probably because the country was in a state of complete turmoil at that time, and many other old processes were also changing. When Britain finally switched to metric system in A.D. 1970, it was also undergoing a large-scale political reform. Because the United States has been relatively static since the constitution was formed, we have no similar opportunities.