there is also another question. the figure you cited for Germany is gross wage. net wage would be €3,324/month, or $45,536/year. is "income", in the US survey, after taxes? i wasn't able to find the definition of "income" in the American Community Survey, but i notice that besides "income", they also have "earnings" (which is higher).
finally, we need to correct for cost of living. i think that would explain a lot of the difference.
* Median household income in Mississippi: $44,717
* Median wage in Germany: €5,370 per month, equals $73,565.
So even the individual median wage in Germany is more than 50% higher than the median household income in Mississippi.
Sources: https://en.wikipedia.org/wiki/List_of_European_countries_by_... and https://en.wikipedia.org/wiki/List_of_U.S._states_and_territ...