"Rum-running" usually means smuggling over water. The term is thought to come from the start of the Prohibition era in the United States. This is when ships from Bimini in the western Bahamas transported cheap rum to Florida to be sold illegally. But there was little profit in cheap rum. They soon started smuggling Canadian whisky, French champagne, and English gin to major cities like New York City and Boston. This gave them a high profit. It was said that some ships carried $200,000 worth of alcohol in a single trip.