- The genocide of Natve American
- Enslavement of people of color from Africa and the Caribbean
- Internment of Japanese Americans
- Jim Crow South

Those are four of the most egregious acts perpetrated and permitted by our government.  If you don't get that we are far from pure you don't get it at all.  The US government has been the source of a huge amount of human suffering right here in the USA and white Americans perpetrated most of it.  Not ALL white Americans and probably not even a majority of white Americans, but it is heinous and needs to be accounted for.