Not necessarily true. Not everyone had to have a passport to travel back to the "old country" even though they might have been naturalized or a citizen born in the US. While passports started in 1789 (the first ones were printed by Benjamin Franklin), they were not mandatory until the Civil War. After the Civil War, it was optional to have one until an Executive Order by President Wilson in 1915 and later an Act of Congress in 1918 (due to WWI) established the passport requirement for citizens traveling abroad. The law lapsed with the termination of WWI and was not strictly enforced. With the onset of WWII in 1941, the Congressional Act of 1918 was reinstated requiring all US citizens to carry a passport for foreign travel as it is today. Bottom line...depending upon when a relative traveled back, they may or may not have had a Passport or applied with a Passport Application which does have a lot of information. Also, US Citizens could travel without a passport to countries such as Canada and Mexico until 2004 when the Western Hemisphere Travel Initiative (WHTI) was signed due to 9/11 to strengthen U.S. border security. As an aside, pictures became part of a passport in 1915.

Phil Goldfarb
Tulsa, Oklahoma
Searching Froug, Leet (Lit in Radeikiai, Lithuania), Gitow (Gitovich in Mogilev, Belarus and Ekaterinoslav, Ukraine) Gruber (Austria) Goldfarb (Kamenits-Litovsk, Russia, now Kamyanyets, Belarus)