I don't want to be like the typical fake white liberal apologist, but I did some digging in my family tree and unfortunately it appears my great great great great grand father through my maternal line had enslaved about 10 people.
Bums me out and makes feel sick to my stomach.
Assuming every member of each generation had three kids, you're one of 729 progeny begotten from that old racist. You have two options: forgive yourself or hunt down the remaining 728 family members to destroy his lineage.
But also, every other white person is just as guilty. It's not about your great great great great grandpa - it's about how all white people today benefit from the systems that people like our great great great great grandpas built. All you can do is try your best to tear down white supremacy in all its forms, same as before you knew this little fact about your family history.