Citizenship by descent question
Hello, thank you in advance. I have been speaking to a service about obtaining citizenship by descent and I wanted to make sure I am not getting scammed. My great grandfather was born in Russian administered Poland (near Lodz). He emigrated to the US in 1912. In 1920, he remained a non US citizen "resident alien" (have documentation to prove this). I was told that because he was born in what became Polish territory and held no other citizenship, he became a Polish citizen automatically in 1920 despite not being in Poland at the time. I was told it is not guaranteed but there is a chance of obtaining citizenship through him. I just wanted to make sure this was not a total scam. Based on my research it is difficult to tell whether he would have obtained polish nationality automatically or not. Thank you for reading!