Connecticut, Maine, Massachusetts, and Rhode Island: Commentary

Massachusetts Atlas of Historical County Boundaries

John H. Long, Editor and Historical Compiler; Peggy Tuck Sinko, Associate Editor; Gordon DenBoer, Historical Compiler; Douglas Knox, Book Digitizing Director; Emily Kelley, Research Associate; Laura Rico-Beck, GIS Specialist and Digital Compiler; Peter Siczewicz, ArcIMS Interactive Map Designer; Robert Will, Cartographic Assistant

Copyright The Newberry Library 2009

Nearly all American states have defined their counties’ areas and limits as lines running from point to point or along specified courses. These New England states are exceptions to that practice, for they commonly defined their counties as groups of towns (incorporated municipalities). In these states a purposeful change for a county was usually accomplished by changing the mix of towns that composed it. Each of these states also altered county areas and bounding lines as the consequence of changing the lines separating towns on opposite sides of a county boundary; when county boundaries were changed in this fashion that effect appeared inadvertent and the affected counties often were never named. The method for discovering such changes requires identifying neighboring cities and towns that could force a county change and then searching for changes. For Massachusetts that task was eased considerably by the Secretary of the Commonwealth’s Historical Data Relating to Counties, Cities, and Towns in Massachusetts (1966), a remarkably thorough and accurate listing of jurisdictional changes among municipalities. A similar collection of data for Maine is Counties, Cities, Towns, and Plantations of Maine: A Handbook of Incorporations, Dissolutions, and Boundary Changes (1940), originally compiled and published by the Historical Records Survey for that state.

In 1763, as part of the peace agreement that ended the Seven Years War, France and Great Britain established the northern limit of Maine as the Atlantic–St. Lawrence River watershed, unchanged since then. Subsequent disputes over Maine’s boundary concerned not its definition but its implementation. Therefore, in this atlas the modern version of the boundary line has been depicted from 1763 onward. Two important changes in Maine were not clear and obvious from the standard sources. The first case concerned Aroostook County, which extended across the northern cap of Maine in 1844. Vague wording in the description of Aroostook’s southern limit could be interpreted to run the county line through a line of western towns, but that would have been contrary to the common practice of preserving the integrity of municipalities, so the county boundary has been plotted along the town lines. The second case involves the boundary that today separates the town of Detroit in Somerset County from the town of Plymouth in Penobscot County. In 1790, this county line ran straight north, cutting through several towns, including Plymouth. Subsequent laws placed the other towns wholly in one county or the other. However, there is no extant law that adjusted the line through Plymouth. An act of 29 February 1844 incidentally mentioned that Detroit and Plymouth were in different counties and implied that such an arrangement was of long standing. Lacking other evidence, it appears that years before February 1844 officials and residents had adopted the town lines as the de facto county lines, so in the chronology that change is dated “by” the date on which the arrangement was so casually revealed.


Every effort has been made to give the day, month, and year (e.g., 25 February 1785) for all county creations, boundary changes, and other events in this atlas. Occasionally it is impossible to date an event so precisely, but a reasonable estimate is possible. When the precise date is not known or an approximate date is more appropriate, the date is generalized to the month and year (e.g., February 1785) or to the year alone. A lack of evidence may make it impossible to give any date at all for a county's creation, and its occurrence can only be confirmed by the record of a later, related happening, such as the appointment of a sheriff. In such a situation, the date of the later event is used with the simple addition of "by" (e.g., by 25 February 1785) to indicate that the county creation or other event occurred no later than that date and probably earlier.

The dating standard in this atlas is the legally effective date of change, whether it be for the creation of a new county or for the alteration of lines between existing counties. Through the colonial period and into the nineteenth century, the date a law passed was generally the date it went into effect. As the nineteenth century progressed, legislators recognized the importance of preparing for the establishment of a new county organization or for the shift in jurisdiction that accompanies boundary changes. Some laws, therefore, began to carry two dates: one marking the passage of the law and the other specifying when the line change or new county creation would go into effect. If the date of passage and effective date are different, the law gives both. Connecticut, however, is an exception. For every county boundary change in Connecticut before 1820, the date given here usually marks the beginning of the legislative session. The sessions were short, dates of passage were not given in the published records, and the opening date of the session is always available.

Using effective dates means that many of the dates in this atlas may disagree with dates in other references. As an aid to appreciating how great the differences between the two dates can be and to help correlate this data with other publications, this work gives both the date of passage and the effective date for all county creations. While the maps are keyed to the effective date, a notation is made in the chronologies giving the date of passage. For example, a new county created by a law passed 15 January 1832, which did not take effect until 1 July 1832, would not be mapped until 1 July. But the chronology would include the entry: “Act passed 15 January 1832; took effect 1 July 1832.”

Dating events before 1752 is a problem because the calendar then in use is very different from the one in use today. Whereas by 1600 most of Europe had adopted the Gregorian calendar, as the modern system of reckoning the days is called, England observed the Julian calendar until 2 September 1752. For the purposes of this atlas, the chief differences between the two systems are, first, numbering the days and, second, designating the change from one year to the next. There has been no attempt to convert the dates of one system to those of the other. Differences in numbering days, therefore, are effectively ignored; whatever day and month are given in a source are the day and month used here, regardless of whether the document was written in England or some other country, before or after 1752. Under the old, Julian calendar the last day of the year was 24 March and the first day was 25 March, which means that in England and its colonies the day after 24 March 1750 was 25 March 1751. This atlas follows the convention of showing both years for dates that fall within the period from 1 January through 24 March when the different calendars call for different years. Thus, successive dates before England's adoption of the Gregorian calendar would occur as follows: the day after 24 March 1688/1689 would be 25 March 1689; the day after 31 December 1689 would be 1 January 1689/1690. About three months later would come 24 March 1689/1690, and the next day after that would be 25 March 1690.