Cyndi's List - Databases: Searchable Online - Immigration, Emigration & Migration

Ancestry.com - Immigration

Searchable indexes; database results and some digitized images available with fee-based subscription.
Ellis Island - FREE Port of New York Passenger Records Search

Online searchable database of over 22 million passenger names covering roughly 70% of the immigrants processed through Ellis Island between 1892 and 1924.
Fylkesarkivet i Sogn og Fjordane - Databases

Norwegian census, land, church, emigration, probate records, etc.
Institute of Migration - Siirtolaisuusinstituutti - The Emigrant Register

Online searchable database of over 400,000 entries from passport, passenger list, and other records of Finns who emigrated.
One-Step Webpages by Stephen P. Morse

Alternate search functions for many online databases. Includes tools for immigration, census, vital records, calendars, soundex, foreign alphabets, Jewish and Holocaust research.
- Castle Garden years (1855-1891) plus other New York Arrivals
- Ellis Island Search Forms and Ship Arrivals
  
  One-Step search of Ellis Island immigration records covering the years 1892 to 1924. Includes Missing Manifests Search and Morton Allan Directory. This search requires a subscription to a pay-for-use database.
- Other Ports of Immigration
Scottish Emigration Database

Online searchable database containing the records of over 21,000 passengers who embarked at Glasgow and Greenock for non-European ports between 1 January and 30 April 1923, and at other Scottish ports between 1890 and 1960.
- Search

Categories