For historic background and access to current foreign policy information, try this week's "Guide of the Week" from the ALA GODORT Handout Exchange Wiki:

Government Documents on U.S. Foreign Policy (Bert Chapman, Purdue University, 1999) Last updated 3/10/2008

Bert truly starts his guide at the beginning with The Revolutionary Diplomatic Correspondence of the United States (6 vols.) and moves on to such current resources such as:

• Foreign Consular Offices in the U.S.
• United States Contributions to International Organizations
• Legislation on Foreign Relations Through (year)
• Commission for Assistance to a Free Cuba
• European Union "Common" Foreign and Security Policy

There's a lot to wander through. So please go wander. And if you're a documents librarian with a handout of your own, please post it to the Handout Exchange Wiki!