Resources

FOREIGN TRADE is the official source for U.S. export and import statistics and responsible for issuing regulations governing the reporting of all export shipments from the United States.
https://www.census.gov/foreign-trade/index.html

United States Census Bureau: Classifications of products, countries, customs districts.
https://www.census.gov/foreign-trade/reference/codes/index.html

U.S. Department of Commerce/International Trade Administration
https://www.trade.gov/index.asp

United States Free Trade Agreements with Foreign Countries
https://www.trade.gov/fta/

State Export Data by State
https://www.trade.gov/mas/ian/statereports/index.asp

U.S. Trade Laws
https://www.trade.gov/mas/ian/ustradelaws/index.asp

The World Bank: Merchandise Trade (% of GDP)
https://data.worldbank.org/indicator/TG.VAL.TOTL.GD.ZS