Most historical documents are compilations within larger sets. The name and location of the set can be found using the library catalog.
However, the catalog will not list the contents of the set. You must use the printed indexes for the set or, if a digital equivalent is available, you can search the set online.
Foreign Relations of the United States (FRUS)
1870-present
S 1.1: Selected volumes also available at various online sites.
FRUS is the official documentary history of the foreign relations of the United States. It consists of over 450 volumes. Documents undergo approximately at 30 year waiting period to become declassified before appearing in FRUS. Find the volumes for the years you need, then use the printed index in the back of the volume.
Congressional Record
1873-present (published daily)
X: Earlier volumes go by slightly different titles. This set is essentially a verbatim account of the remarks made by senators and representatives while they are on the floor of the Senate and the House of Representatives. It also includes all bills, resolutions, and motions proposed, as well as debates and roll call votes. The debates and extension of remarks are especially useful in understanding the background of internal and external national affairs.
Serial Set
1817-present
Print indexes in ACU GovDocs reference collection; see also HeinOnline
Contains the House and Senate Documents and the House and Senate Reports bound by session of Congress. It began publication with the 15th Congress, 1st Session (1817). Documents before 1817 may be found in the American State Papers. Includes committee reports related to bills and other matters, presidential communications to Congress, treaty materials, certain executive department publications, and certain non-governmental publications.