Stop saying "Gustaf says"... 
It's not ME...someone else on the forum wrote about this maybe a year ago. The definition was, IIRC, the intersection point between two lines dividing the US into west/east and north/south halves, population-wise. According to the person writing it, this was Missouri for most of recent times and originally in Maryland.
Nope, that's the definition for the median, which is still east of the Mississippi. The location you give is correct for the mean. I remember the thread...the discussion here is very much like the one back then. The notion is false, btw.
