Great Britain blockaded the ports
Also the US Civil war went badly...
https://en.wikipedia.org/wiki/Lancashire_Cotton_Famine
Curiously the Confederates (controlling an area with most of the US cotton production) thought it would be clever to cut the supply of cotton to the UK.
British didn't react as they expected.
https://en.wikipedia.org/wiki/Lancashire_Cotton_Famine#Politics
Trump steel import tariffs may achieve what Europe, Japan and Korea didn't, the death of North American Auto making.
Sanctions have a history of making ordinary people suffer, making Global companies rich (SA) and often ignore the worst Regimes. Like Iran's Gulf and Arabian enemies.
Biting the hand that feeds IT
