From a total population of 12,319, Marshall County has a median age of 45.8. The average age of males, in Marshall County, is 44.4 while the average age of females is 46.7. When you compare this to median age of Illinois, Marshall County is 8.8 years older.
The median income of individuals, in Marshall County, is $26,399 while the average household income is $53,914. When comparing the median income of people living in Marshall County to the rest of Illinois, the average income in Marshall County is $3,620 less.