[ 5 ]  -  Density 1189/sq mi  (459/km 2 ) Ranked 1st in the U.S.  -  Median household income   $70,378 (2nd) Elevation    - Highest point High Point [ 6 ] [ 7 ] 1,803 ft (549.6 m)  - Mean 250 ft  (80 m)  - Lowest point Atlantic Ocean [ 6 ] sea level Before statehood Province