I wouldn't go as far as calling the people of the US savages but they certainly haven't learned how to get along as well as the Europeans do.
Slavery of local peoples (the people near Sweden) ended in 1335. Slavery of Africans ended in 1847. Unlike the US, Sweden doesn't appear to have a significant number of recent former slaves that need integrating, so I think my point still stands.
Slavery ended in Sweden in 1847[1] (153 years ago), so that can't be it.
1.https://en.m.wikipedia.org/wiki/Swedish_slave_trade