If most modern Americans from families already here in the 1700's were to check their genealogy I believe that most would find a slave owner somewhere in their line. Of course it feels shameful now to a person of our modern culture, but those ancestors lived in a very different time/culture. This acknowledgement in no way makes slave owning okay for us now, but it was okay for them, at least within their own communities.

It isn't easy to read US history from earlier centuries and not feel shame when we realize what our direct predecessors did and thought was acceptable behavior. However that can be carried forward into the last century, even in things as seemingly innocent as movies include stereotypical (for the time) characters from other races and cultures.

In my own family, my great-great grandfather was hired to help remove Native Americans from their traditional lands to make room for the new white settlers. That isn't the same as slave owning, but it carries the same burden of shame for me.