The notch in Connecticut's northern border, just above Granby, is sometimes called the "Southwick Jog".
In 1642 Massachusetts hired two surveyors, Nathaniel Woodward and Solomon Saffery, to survey the boundary between that colony and Connecticut. However, the point they established as the western end of the line was disputed by Connecticut and ultimately found to be eight miles too far south. According to a pamphlet in our vertical file, for the next 60 years, "surveyors hired by either Connecticut or Massachusetts set a number of boundaries favorable to the colony that employed them. The only result of these surveys was increased animosity between the two colonies. Even a joint survey in 1702 did little to settle the affair.
"To complicate matters, the citizens of Enfield, Somers, Suffield and Woodstock, unhappy with Massachusetts' high taxes, applied for admission into Connecticut in 1724. These towns claimed they were included within Connecticut's original boundaries and were entitled to return to that state."
"Naturally, Massachusetts refused to give them up, but in 1749 Connecticut voted to acquire them. A verbal battle raged for years, reaching crisis proportions. Appeals to England were ignored, since that country was embroiled in the Seven Years' War."
"In 1768, Massachusetts laid formal claim to the four towns; however, Connecticut did nothing about the edict and continued to govern them."
Following the Revolutionary War, in 1793, both states appointed Boundary Commissioners to run a straight boundary from Union, Connecticut to the New York state line. In 1797 the Commissioners recommended that a disputed 2.5 square mile tract be awarded to Massachusetts as compensation for its earlier losses of Suffield, Woodstock, Somers, and Enfield to Connecticut. However, it was not until 1804 that Connecticut agreed to yet another compromise that partitioned the 2.5 mile area at Congamond Lakes with Massachusetts receiving 5/8 of the disputed parcel along the west shore and Connecticut receiving the remainder, along the east shore.