'Essex County, MA' definitions:

Essex -- U.S. County in Massachusetts

From: Gazetteer 2000
Name :
Essex -- U.S. County in Massachusetts
Population (2000) :
723419
Housing Units (2000) :
287144
Land area (2000) :
500.667108 sq. miles (1296.721801 sq. km)
Water area (2000) :
327.859826 sq. miles (849.153015 sq. km)
Total area (2000) :
828.526934 sq. miles (2145.874816 sq. km)
Located within :
Massachusetts (MA), FIPS 25
Location :
42.635475 N, 70.970827 W