The first standard meter was a bar of iron, which was prone to elongation / contraction depending on the temperature. Copies were placed around in Paris for people to calibrate their own measuring stick against.
In 1875, the Treaty of the Meter, signed by 17 countries including the U.S., established the General Conference on Weights and Measures (Conférence Général des Poids et Mésures , CGPM)
A new Standard meter bar was created from platinum-iridium alloy.
The original was kept in a temperature controlled cabinet in Paris, but 30 replica meter bars were given to member countries.
Source: https://www.nist.gov/si-redefinition/meter
At the same time 30 additional Standard meter bars were made and distributed among the member nations of the BIPM, incl. USA:
NIST has a lot more info from a US point of view, incl. on "Metrication of US:
And how to understand the metric system:
PS> Since the above come from a US Gov. institution it MUST be accurate and unbiased.