Can You Gain U.S. Citizenship Through a Citizen Grandparent

[Betos]

If my grandfather did become a US citizen years after my mother was born can I still gain US citizenship? Also, my mother is willing to affirm her US citizenship so I can get mine.

[LawResearcherMissy]

If my grandfather did become a US citizen years after my mother was born can I still gain US citizenship?

Maybe.

First, you need to PROVE that he was a citizen. You'll need some documentation.

Then your mother needs to get HER citizenship. THEN you can apply, but it's not guaranteed that you will be granted citizenship.

Citizenship is a complicated process. I would suggest you hire an attorney to help you navigate the system, in particular since you don't seem to have any records proving your grandfather's citizenship, and since your mother was already denied.