International

Australia

National Archives of Australia [www.naa.gov.au/]
National Library of Australia [www.nla.gov.au/]

France

Archives nationales [www.archivesnationales.culture.gouv.fr/]
France-généalogie [www.france-genealogie.fr/]
PREFEN [www.unicaen.fr/mrsh/crhq/prefen/formPion.php]

Great Britain

National Archives (formerly known as the Public Record Office) [www.nationalarchives.gov.uk]
The Family Records Centre [www.familyrecords.gov.uk/frc/]

Ireland

Ireland's Historical Mapping Archive [www.irishhistoricmaps.ie/historic/]
National Archives of Ireland [www.nationalarchives.ie/]

Scotland

National Archives of Scotland [www.nas.gov.uk]
ScotlandsPeople [www.scotlandspeople.gov.uk]

United States of America

The National Archives [www.archives.gov/]
The Library of Congress [www.loc.gov/]
Federation of Genealogical Societies [www.fgs.org/]
Vital Records US [www.vitalrecordsus.com]