Re: Where Do I find these immigrant documents?
The process of immigration to the US, prior to 1924, went as follows:
1) the immigrant applied for travel documents, in every case that I have verified it was a passport
2) the immigrant purchased a steamship ticket
3) at the Port of Departure an employee of the steamship company filled out the ship manifest (some info was completed at sea)
4) the Ship Manifest aka Passenger List was presented to immigration officials at the US Port of Entry
5) Immigrants were processed and most allowed entry into the US and a few were deported for medical or other reasons.It was at the POE that the determination as to whether or not an immigrant could enter the US.
After 1924 immigrants would visit a US Consulate in their home country where they would be processed and it was there that the determination was made as to whether or not an immigrant could enter the US.This came about largely as an anti-foreign sentiment that came about after WW I.Immigration prior to 1914, the onset of WW I, ran about 1,000,000 a year, after WW I it was around 150,000 per year.
So you will find NO application to immigrate to the US amongst US paperwork.And finding any application amongst the places they came from is slim.I have seen some records of immigrants from Croatia to the US during the early 1900s which came from Croatian archives.
FYI prior to the end of WW I (approx 1922) Hungary was part of the Habsburg Empire aka Austria Hungary.That Empire inc all or parts of the modern countries of Aust, Hung, Poland, Ukraine, Russia, Czech Rep, Slovak Rep, Romania, Italy, Croatia, Slovenia, Bosnia and Serbia. So when you say "one set of GPs came from Hungary"you need to specify where they came from!As records may or may not be found in Hungary today or they may be in some other country! The same goes for the old Russian Empire vs the new Russia.
Croatian Heritage Museum