The _Empress of China_ was the first trading vessel that the independent United States sent to China. (Under British rule, the Colonies were forbidden from engaging in trade with Asia.) Among its cargo was 57,687 lbs of ginseng from the mountains of Pennsylvania and Virginia. Who knew that China had to _import_ ginseng? Not me, anyway.
On the return trip, the majority of the ships hold was given over to 284,000 lbs of — what? Anyone? Anyone? Find the answer in the comments.