My 24-year old grandmother came to the US at age from what was then Russia in 1914 using the passport of her 19-year old sister. Her ship sailed from Rotterdam on the day Russia entered WWI. It was an age thing, but I never understood why a 24-year old might not be admitted to the US but a 19-year old would, especially since there were other family members in the US already. When my grandmother's sister eventually came to the US with her four children in 1933, it was under her married name and with a Polish passport.