- Ancestry.com: Provides some online services for free but others require a paid subscription. Useful information can be had without a subscription, though.
- FamilySearch: Created and maintained by The Church of Jesus Christ of Latter-day Saints, this site offers a vast array of genealogical information and research assistance. One of the most useful sites on the Web.
- The USGenWeb Project: Portal to free genealogy sites for counties and states across the United States.
- Local History & Genealogy Reading Room - Library of Congress: Provides access to bibliographies, Web directories, and the Library's local history and genealogy collection catalog. The larger Library of Congress website provides a wealth of information as well.
- National Archives & Records Administration: Enables researchers to locate ancestors within a variety of federal records and documents, including military records.
- Ellis Island: Searchable index of Ellis Island/Port of New York passenger records.
- National Center for Health Statistics: Developed the Research Data Centers (RDC) to allow researchers access to restricted data.