I guess I should have expected it, with so many relatives from Maryland and Virginia. But of course no one talked about it, so how was I to know?
Here's how I found out: among the various effects from assorted great-uncles and great-aunts and such, there was a seal stamp that had lost its handle. It still had the part that makes impressions, though, and that said, "Klabonga" in a flowery script.
At the time I inherited it (I was still in pigtails, I think), I had barely heard of the Klan and thought of it as something nasty that had happened a long time ago. It couldn't possibly have any connection to my family. This was the era of Peanuts and Snoopy thinking "Cowabunga!" as he played surfer on his doghouse roof. And, naive child that I was, I took it as something innocent. I even used it a few times - only for letters to my sister, I hope. (She was even younger and more naive than I - then.)
It was only a few years ago that I learned that seals and insignia and such that began with "Kla--" were used by, and only by, Klansmen.
So yes, someone in my family was Klan.
I still have the seal...I think. I'm undecided whether to "lose" it somewhere, or take it to have the offending slogan ground off and replaced with something else.