1. Congressional Record
Gov. Docs section X. Beeghly owns 1871 - Present
Official recordings of Congressional sessions, including speeches, debates, etc. Also available online at FDsys from 1994 to present.
2. Public Papers of the Presidents
Gov. Docs section: GS 4.113: 1929-1933, 1946-1983 and AE 2.114: 1984-present
Public papers, speeches, etc. of the presidents, officially issued by the Office of the Press Secretary. OWU has most volumes available in print. However, digitized volumes of these papers can be found at various government web sites like FDsys.
*For earlier presidents, like Washington, Jefferson, Madinson, etc., try searching CONSORT or Summon with the president's name and the word "papers." (e.g. washington papers) The library owns several other collections of early presidential papers in print. These collections are also being digitized and some can be found online but are not always free.
Presidential libraries also contain and digitize important items related to the presidents and their terms. The National Archives web site has a great explanation and list of the libraries.
4. Foreign Relations of the United States
Gov Docs section: S 1.1. Beeghly owns 1870-1976 in print
From the Office of the Historian, "series presents the official documentary historical record of major U.S. foreign policy decisions and significant diplomatic activity." Great for topics relating to foreign events or people. Also found...
Online from 1945-1976: Office of the Historian
Online though incomplete from 1861-1960: Univ. of Wisconsin Digital Collection