GOVERNMENT

Federal

 
USA.gov"Government information by topic and agency,” for federal, state, and local government data. The best place to start looking for a topic if you're not sure which agency/agencies would be involved, because it will bring back results from all of them! Everything else included in this list will generally also be findable via USA.gov.
Data.govData and datasets collected by federal agencies, collected in one place for discovery and use.
Catalog of US Government Publications"The finding tool for federal publications that includes descriptive records for historical and current publications and provides direct links to those that are available online.”
GPO Federal Digital System (FDSys)"Free online access to official publications from all three branches of the Federal Government,” such as laws and bills, hearing documents, federal codes, presidential speeches, and more.
Congress.govU.S. legislative documents, videos, and data, as well as a directory of current and past Congresspeople.

Local & National

 
U.S. CensusDemographic and economic information and datasets collected by the U.S. Census, searchable by topic (education, housing, income level, population, etc.) or geographical area.
American FactFinderCensus data searchable by community.

International

 
CIA World FactbookThe World Factbook "provides information on the history, people, government, economy, geography, communications, transportation, military, and transnational issues for 267 world entities”, including maps, with information from a wide variety of government agencies.
US Bilateral Relations Fact SheetsThe history of U.S. involvement with each country, from the State Department.

 

SCIENCE & TECHNOLOGY

Department of Energy Data Explorer"Science, technology, engineering research and data collections from the U.S. Department of Energy.”
National Library of EnergyA "one-stop, easy access to DOE information in four broad topic areas: science and R&D, energy and technology for industry and homeowners, energy market information and analysis; and nuclear security and environmental management."
Integrated Taxonomic Information SystemITIS provides "authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.”
US Geological Survey Natural Hazards MissionThe U.S. Geological Survey (USGS) collects research and data on Coastal & Marine Geology, Earthquake Hazards, Geomagnetism, Global Seismographic Network, Landslide Hazards, and Volcano Hazards.
USGS Publications WarehouseA collection of "over 100,000 publications written by USGS scientists over the century-plus history of the bureau."
Science.govThe results of federally funded science research: "200 million pages of authoritative U.S. government science information including research and development results.”
National Center for Science and Engineering Statistics"Data on research and development, the science and engineering workforce, the condition and progress of STEM education, and U.S. competitiveness in science, engineering, technology, and R&D.”
National Institute of Standards and Technology Data GatewayProvides access to the National Institute of Standards and Technology's (NIST, from the U.S. Department of Commerce) scientific and technical data, searchable by keyword as well as by property (such as density) or substance (such as benzene).

 

ECONOMICS

Bureau of Labor StatisticsThe Bureau of Labor Statistics (BLS) tracks American employment, price index, inflation, and productivity.
Economic Research and Data (Federal Reserve)"Economists at the Federal Reserve Board conduct innovative research on a broad range of topics in economics and finance. In addition to presenting their research to policymakers, Board economists share their research at academic conferences and publish it in peer-reviewed journals and other scholarly outlets."
Bureau of Economic AnalysisThe BEA tracks Gross Domestic Product, consumer spending, international trade and balance of payments.
EDGAR (SEC Filings and Forms)"All companies, foreign and domestic, are required to file registration statements, periodic reports, and other forms electronically through EDGAR." Publicly traded companies in particular must file annual reports showing their performance, making EDGAR a valuable source of company research.

 

HEALTH & MEDICINE

National Library of Medicine (NIH)"The world’s largest biomedical library, NLM maintains and makes available a vast print collection and produces electronic information resources on a wide range of topics”; includes databases PubMed, Medline, MeSH, etc.
PubMedPubMed is the database where the publications resulting from federally funded biomedical research are deposited. It "comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites."
National Center for Health StatisticsThe National Center for Health Statistics collects statistics compiled through Centers for Disease Control research on health and medical issues in the U.S. and abroad.