US Customary Units Are Defined by Metric Standards
Veritasium · Explainer · 9 min · 2017 · YouTube title: Is America Actually Metric?
Why it's here
HN commenters link it to show that the US is effectively metric because its customary units are defined from SI.
What it covers
Veritasium explains that the US signed the Metre Convention in 1875 and that all US customary units are officially defined in terms of metric standards. It also touches on the standard kilogram.