Why does Massachusetts have a strange notch in Connecticut? The history of the Southwick Jog

The boundary between Massachusetts and Connecticut is one of the oldest interstate borders in the United States. For most of its length, it follows an almost straight east–west line across southern New England. Yet near the town of Southwick, Massachusetts extends southward into Connecticut, creating a small rectangular projection commonly known as the Southwick Jog. From Connecticut's perspective, the same feature is called the Southwick Notch, because it resembles a piece cut out of the state's northern edge. Although the irregularity covers only about two square miles, its origins involve nearly two centuries of colonial disputes, inaccurate surveys and competing political claims. The problem began in 1642, when surveyors working for Massachusetts placed the colonial boundary several miles too far south. Subsequent attempts to correct the mistake created disagreements over the jurisdiction of entire towns, while local inhabitants sometimes preferred one colonial government over another. The modern notch emerged from a compromise finalized in 1804, long after the original surveying error. Its history demonstrates how the political geography of the United States was shaped not only by wars and large territorial acquisitions but also by local disputes over taxes, settlement rights and the interpretation of seventeenth-century royal charters.

The Strange Geography of the Southwick Jog

The northern boundary of Connecticut appears relatively simple on most maps. Beginning near the New York state line, it extends eastward across southern New England, separating Connecticut from Massachusetts. Although small irregularities exist, the general impression is of a straight line dividing two neighboring states.

Near Southwick, however, the boundary makes an abrupt turn southward, continues for approximately two and a half miles, and then returns northward. The resulting projection forms a nearly rectangular piece of Massachusetts surrounded by Connecticut on three sides.

The territory lies between the Connecticut towns of Suffield to the west and Granby to the east. It forms the southernmost part of Southwick, a Massachusetts town located south of Westfield and near the Congamond Lakes.

Unlike the Kentucky Bend, where a river separates a piece of one state from its main territory, the Southwick Jog remains physically connected to Massachusetts. It is therefore not an exclave. Geographers describe this type of territorial projection as a salient: a section of one political jurisdiction that extends conspicuously into another.

The peculiarity is especially noticeable because the surrounding border is otherwise so regular. A small rectangular extension appears inconsistent with the logic of a boundary supposedly established along a single latitude.

Yet the notch was not deliberately designed as an unusual geographical feature. It emerged from attempts to resolve disagreements that had developed long before Massachusetts and Connecticut became American states.

The most important early problem was that English colonial authorities did not possess an accurate understanding of the region's geography. Their royal charters described enormous territories using rivers, coastlines and astronomical coordinates, but the physical boundaries often remained uncertain until settlers and surveyors attempted to locate them.

Colonial Charters and the Rival Claims of Massachusetts and Connecticut

Massachusetts and Connecticut developed as separate English colonial settlements during the seventeenth century. Their political origins were closely connected to Puritan migration, but their governments emerged under different institutional arrangements.

The Massachusetts Bay Colony received its royal charter in 1629. Its southern boundary was described partly through a line extending westward from a point three miles south of the southernmost part of the Charles River.

This definition appeared straightforward, but it depended on accurately identifying the relevant geographical point and extending a line across territories that had not been systematically surveyed.

The English settlements that eventually formed Connecticut developed farther south along the Connecticut River and the Long Island Sound coast. Towns such as Hartford, Windsor and Wethersfield established political institutions of their own, while the surrounding region contained Indigenous communities whose territorial relationships predated European settlement.

The early English colonies did not always agree about which settlements belonged under which government. The Connecticut River valley was particularly contested because it provided fertile agricultural land and an important transportation route into the interior.

Springfield offers an example of these overlapping claims. Founded in the 1630s by William Pynchon and other English settlers, it initially possessed strong connections with the Connecticut River settlements farther south. However, political and commercial disagreements encouraged Springfield to align with Massachusetts.

The decision had lasting geographical consequences. Springfield became an important Massachusetts settlement on the Connecticut River, strengthening Massachusetts's claim to territory farther south and west than Connecticut leaders considered appropriate.

The resulting disagreement was not simply a contest between two abstract royal charters. It involved particular settlements whose inhabitants wanted predictable laws, land titles, taxation and access to government institutions.

As the colonies expanded, establishing the northern boundary of Connecticut became increasingly important. Massachusetts officials therefore organized a survey intended to determine where their southern territorial limit should lie.

That survey created the problem that eventually produced the Southwick Jog.

The Surveying Mistake of 1642

In 1642, Massachusetts appointed Nathaniel Woodward and Solomon Saffery to determine the colonial boundary. Their task was to locate the line established by the Massachusetts charter and extend it westward.

The surveyors faced considerable practical difficulties. New England contained extensive forests, rivers, wetlands and relatively few established roads. Accurately maintaining a line of latitude across such terrain required instruments, astronomical knowledge and surveying methods that were not always available or consistently applied.

Woodward and Saffery adopted an unusual approach. Rather than continuously surveying the boundary overland, they traveled by water around Cape Cod and into the Connecticut River system before attempting to establish the line farther inland.

Their measurements were inaccurate. The line they identified lay approximately seven or eight miles south of the boundary implied by the Massachusetts charter.

This was a substantial error. It placed extensive territory under Massachusetts's claimed jurisdiction, including communities that Connecticut would later argue belonged within its own boundaries.

Massachusetts accepted the survey as an authoritative interpretation of its southern frontier. Connecticut, however, disputed its accuracy and maintained that the line had been placed too far south.

The disagreement became more serious as settlements expanded into the affected region. Towns established under Massachusetts authority found themselves within areas that Connecticut considered part of its rightful territory.

The surveying error therefore acquired consequences that extended far beyond cartography. Residents could receive competing demands for taxes, face conflicting legal claims and find their local political institutions challenged by another colonial government.

The original mistake was relatively easy to describe once more accurate measurements became available. Correcting its political consequences proved much harder.

Why Connecticut and Massachusetts Fought Over Entire Towns

During the late seventeenth century, Connecticut attempted to establish a more accurate version of the boundary. A new survey was carried out in 1695, and further joint surveying work followed in 1702.

These investigations supported Connecticut's argument that the original Massachusetts survey had placed the line too far south. However, Massachusetts was reluctant to surrender territories that had already been settled and administered under its authority.

The dispute particularly affected Suffield, Enfield, Somers and Woodstock. These communities had developed strong connections with Massachusetts, but their geographical positions made them subjects of Connecticut's competing territorial claim.

The interests of the inhabitants did not necessarily coincide with the preferences of either colonial government. Local communities considered taxation, political representation and the convenience of administrative relationships when deciding which colony they preferred.

In 1713, Massachusetts and Connecticut reached an agreement intended to settle the matter. Connecticut accepted a financial arrangement under which Massachusetts retained the disputed territory.

However, the settlement did not enjoy universal local support. Some residents continued to believe that Connecticut offered more favorable political and economic conditions.

The conflict revived during the following decades. In 1749, Connecticut formally accepted Suffield, Enfield, Somers and Woodstock into its jurisdiction, challenging the earlier agreement and provoking renewed objections from Massachusetts.

These changes demonstrate why the border controversy lasted so long. Once settlements had developed, the dispute was no longer merely about the proper location of a latitude line. The governments also had to consider the practical consequences of transferring towns between jurisdictions.

Residents had established farms, churches, property arrangements and local institutions under particular colonial authorities. Changing the political boundary could alter taxes, courts, representation and public obligations.

The conflict therefore became a negotiation over established communities rather than a simple correction of a surveying error.

By the middle of the eighteenth century, Connecticut exercised authority over the principal disputed towns, but several unresolved irregularities remained along the frontier. One of these involved the settlement that would become Southwick.

Southwick and the Emergence of the Notch

Southwick originally developed as a southern section of Westfield, Massachusetts. Its settlement was associated with agricultural expansion into the lands west of the Connecticut River valley.

The area contained farms, woodlands and the Congamond Lakes, a group of lakes that later became important geographical reference points in the boundary dispute.

As the settlement grew, Southwick acquired a more distinct local identity. It was established as a district separate from Westfield in 1770 and subsequently developed its own municipal institutions.

However, the southern portion of Southwick lay within the area affected by the unresolved Massachusetts–Connecticut boundary disagreement.

In 1774, part of southern Southwick came under Connecticut's jurisdiction and was associated with the town of Simsbury. This change reduced the territory administered as part of Southwick and created new questions about the political position of local residents.

The timing was especially significant. The American Revolution began the following year, transforming the English colonies into independent political communities. Yet the removal of British authority did not automatically resolve the territorial disagreements that had developed under colonial rule.

When Connecticut and Massachusetts became states within the new United States, they inherited the old controversy.

In 1786, the Connecticut town of Granby was formed from part of Simsbury, and the disputed southern Southwick territory became associated with the new municipality.

The region therefore passed through several administrative arrangements while the broader interstate boundary remained unsettled.

For residents, these changes were not purely symbolic. Political jurisdiction determined which government could impose taxes, organize elections, administer courts and regulate property.

The Congamond Lakes became particularly important in the eventual settlement because they provided a recognizable geographical feature through which the disputed territory could be divided.

Rather than moving the entire area into one state, negotiators eventually accepted a compromise that separated eastern and western portions of the former Southwick territory.

This agreement produced the strange projection visible on modern maps.

The Compromise of 1804

By the end of the eighteenth century, Massachusetts and Connecticut increasingly recognized that their historical boundary disagreements required a durable settlement.

The two states appointed commissioners to investigate disputed sections of the frontier, examine earlier surveys and develop an acceptable political compromise.

During the 1790s, negotiations addressed the long-standing inconsistencies between the intended colonial boundary and the territories actually administered by the neighboring governments.

The Southwick area remained particularly contentious. Massachusetts argued that it deserved territorial compensation for lands and settlements it had relinquished elsewhere along the border. Connecticut maintained that the proper boundary should correspond more closely to the original charter provisions.

A compromise gradually emerged during 1803 and 1804. The disputed Southwick territory was divided, with the area east of the Congamond Lakes remaining under Connecticut's jurisdiction and the western portion being assigned to Massachusetts.

The resulting boundary preserved a small southward extension of Massachusetts territory. Instead of following the otherwise nearly straight interstate line, the border turned southward around the land retained by Massachusetts and then returned northward.

The settlement produced what became known as the Southwick Jog.

Its shape was therefore not the direct result of the 1642 survey alone. The original surveying mistake created the larger dispute, but the specific modern notch emerged from a negotiated territorial settlement more than 160 years later.

This distinction is important because popular accounts sometimes suggest that a surveyor simply made a rectangular mistake and the states never corrected it. The actual process involved repeated measurements, changing colonial jurisdiction, local political preferences and deliberate interstate compromise.

Even after the Southwick settlement, a few other boundary questions remained. The final significant adjustment along the Massachusetts–Connecticut frontier occurred in 1826, when the states resolved a small irregularity near the Union and Woodstock area.

By that time, the principal territorial disagreements inherited from the colonial period had finally been settled.

Why the Border Was Never Straightened

From a modern geographical perspective, the simplest solution might appear to be replacing the Southwick Jog with a straight boundary.

However, interstate borders are not determined solely by cartographic convenience. They are legal boundaries established through historical agreements, legislation, surveys and administrative practice.

Once Massachusetts and Connecticut accepted the compromise of 1804, the unusual line acquired legal significance. The land within the projection became part of Massachusetts, and local institutions developed accordingly.

Straightening the boundary would require another political agreement transferring territory from Massachusetts to Connecticut. Such a change would also involve questions concerning property, taxation, municipal administration and the legal rights of affected residents.

Because the area is small and the border causes relatively few serious administrative problems, neither state has possessed a compelling reason to reopen the settlement.

The notch has consequently survived despite its unusual appearance.

Its existence has also become part of local historical identity. Residents and visitors sometimes refer humorously to the idea of Connecticut recovering the lost territory, while the projection remains a recognizable geographical feature in regional maps.

The Congamond Lakes make the arrangement especially noticeable. Their waters and surrounding recreational areas lie close to the interstate boundary, creating situations in which ordinary local activities take place near an irregular political division.

Nevertheless, the border does not function as an international frontier. People travel freely between Massachusetts and Connecticut, and the two states cooperate within the broader constitutional framework of the United States.

The territorial anomaly is therefore much more significant historically than it is as an obstacle to daily movement.

Its greatest importance lies in the way it preserves the decisions of colonial and early American governments within the modern landscape.

What the Southwick Jog Reveals About American State Borders

The Southwick Jog demonstrates that seemingly simple internal boundaries can have exceptionally complicated histories.

Its origins lie in the attempt of English colonial authorities to define political territory using a geographical description that could not be applied accurately with the available surveying methods.

The incorrect measurements of 1642 expanded Massachusetts's territorial claims southward and produced disputes with Connecticut over settlements that developed under competing governments.

Later surveys clarified the geographical problem but did not resolve the political consequences. Towns had already established economic and administrative relationships, and their inhabitants sometimes preferred one jurisdiction over another.

The eventual settlement therefore required a compromise that accepted historical realities rather than merely reproducing the original charter boundary.

This is why the modern border contains its distinctive rectangular projection. Massachusetts retained a small piece of the contested Southwick territory, while Connecticut obtained other areas associated with the same dispute.

The irregularity also belongs to the larger history of European colonial expansion in New England. The land was not politically empty before English settlers arrived. Indigenous peoples inhabited and used the territory according to political and geographical relationships that were not reflected in the competing colonial charters.

The later dispute between Massachusetts and Connecticut took place within a system of colonial territorial claims that had already transformed the region's political geography.

As American independence replaced British colonial rule, those inherited claims became boundaries between states. The federal structure of the United States allowed the historical settlement to survive, even though the line no longer corresponded to any obvious geographical necessity.

The modern Southwick Jog is therefore not merely a surveying mistake frozen on a map. It is the outcome of a long process in which geographical uncertainty produced political rivalry, rival governments attempted to establish their authority over settled communities, and a negotiated compromise created an enduring territorial anomaly.

Unlike interstate disputes that culminated in militia confrontations or Supreme Court judgments, the Southwick controversy was ultimately resolved through agreements between the neighboring states.

The result illustrates a central feature of political geography: once territorial boundaries become connected to institutions, property and local identity, they can survive for centuries even when their original purpose has disappeared.

A small rectangular projection along an otherwise straight border thus preserves the memory of seventeenth-century colonial ambitions, inaccurate geographical measurements and the difficult transformation of contested frontier settlements into the established territory of modern American states.