The poorest US states are wealthier through redistribution of wealth to them from other states.
Looking at income per person really misses some important factors of a societies real riches.
A Mississippian is free to eat themselves to death (enabled by Americans' wealth) in a way that Europeans simply can't.
White people in Mississipi had a infant mortality rate close to the national average at 5.8. Which still means it's 50% more likely that a birth result in the infants death the the USA than in Europe. The fact that black people in Mississipi has a infant mortality rate of 16 should really shock you, and indicates that something is seriously wrong somewhere.