Great Britain, the United States, and France were at the head of aviation in its early days. Great Britain and the United States used the imperial system, meaning their aircraft used imperial units. The French, however, used metric, but they became less involved in aviation’s units as the British and Americans continued to dominate the market.

Russia, like France, also uses metric, meaning that their aircraft also use metric rather than imperial. This is the same for other countries such as Japan, North Korea, and China. Russia has began to use feet in its aircraft after starting to transition in 2017.

So it’s rather a Great Britain and US way of doing things than only a US way of doing things.