I may be wrong but I think its the Mississippi River. Sorry if I'm incorrect :(
I am not going to be one of the people that answer nonsence.
thanks for asking!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Mississippi
Biggest river in Europe: YesBiggest river in the world: No (it is in fact the Nile, in north Africa)
No.
If by through, you mean just by touching it's border it counts, it could be the Mississippi