Hampden County originated as part of Hampshire County and consisted of three towns purchased from the Agawam Indians: Springfield (1636), Northampton (1653), and Hadley (1659).
The shire, or seat of power, was split between Northampton and Springfield. The location for the annual meeting would alternate, and clerks would transport court records between the two locations. Because maintaining two offices and ferrying documents between them was costly and dangerous, the legislature approved an act in 1794 that made Northampton the shire town of Hampshire County.
Hampshire County continued to expand, in spite of this change. Springfield’s population alone nearly doubled in size between 1790 and 1810. This growth, among other factors, influenced congress to divide the county. In February 1812, the southern division became Hampden County, with Springfield as the shire town.
The original towns incorporated in the county were: Springfield, Longmeadow, Wilbraham, Monson, Holland, Brimfield, South Brimfield, Palmer, Ludlow, West Springfield, Westfield, Montgomery, Russell, Blandford, Granville, Southwick, Tolland, and Chester.
The agreement of settlement made between Hampden and Hampshire counties in November 1812 can be found in the Court of Sessions Record Book 1, pages 5-6 of the Hampden County Commissioners’ Archives, housed in the Registry of Deeds.
For more on the history and people of Hampden County, read Our County and its People: a History of Hampden County, Massachusetts by Alfred Minott Copeland.