New Haven County, CT
History
Following the process of unification of New Haven Colony with Connecticut Colony in 1664–65, cohesion could be improved. New Haven County was constituted by an act of the Connecticut General Court on May 10, 1666, along with Hartford County, Fairfield County, and New London County. As established in 1666, New Haven County consisted of the towns of Milford, New Haven, and Guilford.Source: Wikipedia
Modern Day Adjacent Counties
Hartford County (north)Middlesex County (east)
Fairfield County (west)
Litchfield County (northwest)