Databases share similiar characteristics, but the list of citations retrieved may be quite different based on scope, coverage, and audience.

CQ Electronic Library - An extensive reference resource comprised of fourteen separate modules, each with its own focus, for researching American government, politics, history, public policy and current affairs.

CRS Reports. Congressional Research Reports offer high quality analysis of current topics.

Foreign Relations of the United States - provides an official documentary historical record of major foreign policy decisions and diplomatic activity since 1861.  For other volumes, see http://history.state.gov/historicaldocuments 

Homeland Security Digital Library - Includes U.S. policy documents, national strategy documents, theses and research papers from the Center for Homeland Defense and Security and the Naval Postgraduate School.

PAIS International  - Covers literature of public affairs including political, economic and social issues and includes references to articles, books, government documents, statistical directories, research reports, conference papers and publications of international agencies. 

ProQuest Congressional (1789-present)  - An index to Congressional publications with full-text for some components of Hearings, Reports, and Congressional Research Service Reports.

RAND- A source of independent fact-based analysis of social, economic and international security issues.

U.S. Congressional Serial Set (1817-1980) with American State Papers (1789-1838)  - Bound, sequentially numbered volumes of all Reports, Documents and Journals of the U.S. Senate and House of Representatives. ASP is a topic-based collection of like publications.  Both are full-text complete with maps, illustrations, and tables.