After the 13 colonies beat Britain in the Revolutionary war, the new country was looking for trading opportunities and build a domestic manufacturing base.
China had opened up to Western Powers and the US saw it as a big country to sell their own goods.
There was a huge local population but the local Chinese were not really interested in US or European products as a whole.
However, the United States did find niche markets for several products including Fur, to be sold in Northern China which gets really cold. The Americans were also able to find a market for sandalwood, which was popularly used to make Chinese Furniture.
The Americans were also able to sell the Ginseng Plant, which to date, is widely used in China as a cure for illnesses.
