As I remember, they made money through shipping it out of China. The father and grandfather of Sarah Delano Roosevelt, FDR’s mother, made the money.
I've lately been looking at the notion that New York is pretty much the center of Globalist Crony Capitalism power. This bit of information is another supporting piece of evidence.
The process went like this: get boat in New York Cit, sail to India, load up on opium, sail to China, sell opium to Chinese, don’t get killed in the process, use money from opium sales to buy ‘exotic Oriental goods”, sail to San Fransisco, sell “exotic Oriental goods”, take pile of money back to New York City, retire to newly purchased estate.