Why is there an assumption that white people have generational family wealth?

Whenever the subject of white privilege comes up, family wealth is brought up. It is assumed that all white people have privilege simply because of skin color. I for one have no family wealth. Nothing passed down from previous generations. No land, no money, not so much as a knick knack. Nothing. My family tree is full of coal miners and farm laborers. Why is it assumed that I have anything other than what I've earned for myself?

Why is there an assumption that white people have generational family wealth?
Post Opinion