Bureau of Economic Analysis - compiles balance of trade and balance of payments data, US investment abroad and foreign investment in the US
FITA Global Trade Portal - International Trade Web Resources compiled by the Federation of International Trade Associations (FITA).
Harmonized Tariff Schedule of the United States
Import Export Guide - Part of the US Federal Government's Business.gov website, this section offers insights, rules, FAQs, and other information to help companies interested in international trade
International Trade Centre - a site by the United Nations and the World Trade Organization
Manufacture America - part of the International Trade Administration of the US Government
National Trade Estimate Report on Foreign Trade Barriers - Office of the United States Trade Representative - reports divided by country; they also have other reports
Trade Information Center - The US Department of Commerce International Trade Administration has 2,500 trade experts in 70 countries.
United States Census Bureau Foreign Trade Statistics