Essex County, NJ
History
Essex was originally formed as one of four administrative districts within Province of East Jersey in 1675, together with Bergen, Middlesex and Monmouth districts. Essex County was formed within East Jersey on March 7, 1683. The county was named after the English county of Essex. When the provinces of East Jersey and West Jersey were combined in 1702, the county boundaries were retained.Portions of Essex were taken in 1741 and transferred to Somerset County. In 1837, Passaic County was formed from portions of Essex and Bergen counties. In 1857, Union County was created from parts of Essex County.
Source: Wikipedia
Modern Day Adjacent Counties
Passaic County – northBergen County – east
Hudson County – east
Union County – south
Morris County – west