u/CharacterLow2692

I am wondering if my family and I can declare German citizenship by descent. Here's what I know:

• My grandmother, who is still alive, was born and raised in Germany.
• She was born in Rosenheim in August 1932.
• She traveled to the US in 1954 to marry an American she met after the war.
• They got married in the US, in Maryland/DC in December 1954 (according to her).
• She and her husband moved back to Germany in April 1955.
• When she traveled back to Germany in 1955, the ship manifest says her naturalization date was March 8, 1955. (less than 4 months after first arriving in the US and just 3 months after marrying an American).
• My father was born in Berlin in September 1955.
• He received paperwork upon his birth declaring that he was an American born overseas.
• He has never held a German passport, but lived in Germany primarily until he was in his 20's.
• I was born in the US in 1988.
• I am married and have three kids born in the last 5 years.

Questions:

• Am I eligible to claim German citizenship by descent?
• Does my father have to claim it first or at all to make me eligible?
• If I am eligible, what paperwork or proof do I need? How would I go about finding it?

Thanks in advance!