The International Trade Administration has a tool called TradeStats Express which provides "data on U.S. goods trade at the national, state and metropolitan area levels." The U.S. Census Bureau also has a number of resources that may be useful. USA Trade Online allows you to track commodities from states by HS or NAICS codes and the Census Bureau also tracks some data regarding exports by metropolitan area. If you're interested particularly in agricultural products, the USDA Economic Research Service has 'State Exports, Cash Receipts Estimates' and 'State Trade by Country of Origin and Destination', both of which seek to provide information on commodities traded by state though the site warns this information is hard to trace with complete accuracy.
Make an appointment with a 