Maritime question of the month answer

In the early days of the American Merchant Marine, what were supercargoes?

Supercargoes were the innovation of Elias Hasket Derby, the father of the U.S. Merchant Marine, after the Revolutionary War. To relieve sea captains of the business aspects of trading, the position of supercargo was created. Supercargoes became responsible for handling the exchange of goods carried in Derby bottoms. Supercargoes became experts in foreign commerce, leaving the captain free to navigate.