Search the following sites & databases for materials relevant to your countries.
"This series presents the official documentary historical record of major U.S. foreign policy decisions and significant diplomatic activity. It is comprised of more than 600 books beginning with Abraham Lincoln's administration in 1861 and continuing to the administration of Jimmy Carter in 1980" (Hein Online description).
Access FRUS online through Hein Online.
Related documents prior to FRUS:
Diplomatic correspondence of the United States : inter-American affairs, 1831-1860
American State Papers -- Legislative and Executive Documents of Congress, 1789 - 1938.
Papers relating to foreign affairs - 1861 - 1868.
The United States Department of State focuses on foreign policy. Their website contains policy issues, press briefings, and a wealth of other materials on policy issues in a site that is well-organized for finding information on specific areas of interest.
Earlier U.S. Department of State Documents
U.S. Department of State Dispatch
Monthly report of US foreign policy, 1990 - 1999. Available online and in print.
U.S. Department of State Bulletin
The earlier version of the Dispatch, 1939 - 1989. Available online and in print.
American Foreign Policy: Current Documents (1956 - 1967)
Available in print at Ekstrom Library, 3rd floor, E744 .A45.
American Foreign Policy: Current Documents (1981 - 1991)
Available in print at Ekstrom Library, 3rd floor, E744 .A45.
American Foreign Policy: Basic Documents, 1977-1980.
Available in print at Ekstrom Library, 3rd floor, E744 .A45.
American Foreign Policy: Basic Documents, 1950-1955.
Available in print at Ekstrom Library, 3rd floor, E744 .A448 1957.
A decade of American foreign policy: basic documents, 1941-1949.
Available in print at Ekstrom Library, 3rd floor, JX1416 .A47 1950