The one line I don't have a bajillion generations back for is my maternal grandmother's grandfather. Died while ggrandmother was in utero, only one other sister my grandmother didn't know (and cousins she didn't know) because her mother had moved to TX, leaving her sister in LA before telephones were really a thing.

Zero male offspring, so DNA testing was out. He was about 20 when he got married, but seemed to have come to the US after age 10, so no previous census records anywhere.

On a whim, since I couldn't find a marriage record for him and my gggrandmother, I wrote to the LA archives with a $5 check. I just got back a copy of the marriage certificate, it mentions where he's from, and identifies both his parents HOLY FUCKING SHIT YESSSSSSSSSS.

Anyhoo, just wanted to celebrate.