Your Guide to Finding
Passports and Passort Applications
Passports obtained in the U.S.
1920 passport application
U.S. Passport Application for Margaret Coyle Gibson
An interesting blog in two parts that talks about finding information on passport applications and highlights differences in what you might obtain from using more than one source.
Passport collection at Ancestry.com
(subscription database, but you can search for free)
About the passport collection
(give it time-- about 5 minutes of advertising at the beginning)
Guide to Finding Passports
Passpors obtained in other countries
Jewish Genealogical Society
Lithuania Internal Passports Database 1919-1940
Polish Aliyah Passports