Hampshire County, MA
History
Hampshire County was constituted in 1662 from previously unorganized territory comprising the entire western part of Massachusetts Bay Colony. It included the original towns of Springfield, Northampton, and Hadley. The original Hampshire County included territory that is now in modern-day Hampden County, Franklin County, and Berkshire County, as well as small parts of modern-day Worcester County. By 1683, three new towns (Westfield (now Southwick), Suffield, and Enfield) had been incorporated south of Springfield. These towns were partly or wholly in the modern state of Connecticut at the time of their incorporation and resulted in a border dispute between the Connecticut Colony and Massachusetts Bay Colony.In 1731, Worcester County was created, which included the original town of Brookfield (incorporated in 1718 as part of Hampshire County). More territory was lost to Worcester County in 1742 when the town of Western (now Warren) was created and added to Worcester County. Further territorial losses occurred in 1749 when the towns of Enfield, Somers (split off from Enfield in 1734), and Suffield unilaterally joined Connecticut Colony. In 1761, Berkshire County was created resulting in even more territorial loss for Hampshire County. In 1811, Franklin County was split off from the northern part of Hampshire, and in the following year, Hampden County was split off from the southern part of Hampshire.
Source: https://en.wikipedia.org/wiki/Hampshire_County,_Massachusetts