Search America's historic newspaper pages from 1777-1963 or use the U.S. Newspaper Directory to find information about American newspapers published between 1690-present. Chronicling America is sponsored jointly by the National Endowment for the Humanities and the Library of Congress.
This link takes you the Digital Collections of the Library of Congress. In addition to Chronicling America, you might also check Department of Defense Annual Reports, Executive Branch Federal Government Web Archive, Frontier Diplomacy: The Foreign Affairs Oral History Collection, Intergovernmental Organizations Web Archive, Legislative Branch Web Archive, and Science Blogs Web Archive.
This collection of U.S. government documents includes The Atomic Bombing of Hiroshima and Nagasaki, Navy Nuclear Weapons Safety, "FACE OFF" NUCLEAR POWER, 12 NOVEMBER 1987 (recording of debate between Sen. Ted Kennedy & Sen. Alan Simpson), and treaties, memos, papers, and other documents from various administrations and departments.
At this site, you can find oral history material documenting John Adams' opera Doctor Atomic, 1982 campaign ephemera on Proposition 12 (nuclear freeze), and other atomic/nuclear items.
"Voices of the Manhattan Project" is a joint project by the Atomic Heritage Foundation and the Los Alamos Historical Society to create a public archive of our oral history collections of Manhattan Project veterans and their families.