I had a similar experience where a black student was soap-boxing about how all white people should feel guilty about slavery because "our ancestors" enslaved "their ancestors".
I laughed and said, "My parents came to this country in the early 70's. All of my ancestors were in Ireland during the slave days in this country. I'm sure you are aware that Fredrick Douglas actually admitted that he was somewhat embarrassed that he was arguing for the plight of slaves in Ireland when he noted that the Catholics in the country were living in conditions that even a former slave found to be intolerable. I'm sure you are also aware that it was Irish dock workers that inspired Mr. Douglas to gain his freedom by commiserating with his plight when he was a boy."
I continued, "Come to think of it, though, I doubt you are aware of these facts. They don't coincide with your theories based solely on the color of my skin. In your distorted view of reality, I'm white, I'm American, so I must have some sort of ancestral complicity with the enslavement of black people in this country. Nevermind that my people were too busy trying not to starve to death to enslave anyone. Nevermind that I have absolutely no roots in this country besides the ones my parents planted. Nevermind that I most likely have ancestors that shared the plight of the African by way of "indentured servitude" in the Caribbean and Australia. Those little details wouldn't fit your simple-minded interpretation of reality. All you see when you look at me is "white" and, in your racist mind, that automatically means "guilty". But of course, Fredrick Douglas would probably disagree with your interpretation, and that's all I really need."
My soap-box was bigger than his. :mrgreen: