In 1740, George II of England established the boundry between New Hampshire and Massachusetts. This moved the towns in Cheshire County into New Hampshire.
But because of the hostilities, no further legal activities related to Chesterfield took place until 1752, when New Hampshire issued the Chesterfield charter.
This map, taken from the actual charter in Concord, shows the 1753 boundry lines. The the same lines that we have today.