Genealogical Clusters

Photograph of couple being married, surrounded by friends and familyGenealogical clusters develop when offspring of families marry spouses who are related to them by blood, marriage, social position, or wealth—often continuing for generations of marriages.

I have written about clusters before , I often uncover them while researching the Early New England Families Study Project (ENEF) families as associated groups, rather than only by single lines of descent.

Take for example the family of EDWARD JACKSON (EF),1 on whose ENEF sketch I am currently working. Edward was a post- Great Migration Begins immigrant, arriving in New England in 1642 or 1643 with his first wife, Frances (married in England in 1631) and their four surviving children. Then in 1649, Edward married Elizabeth (Newgate) Oliver, widow of JOHN OLIVER (EF), whom she had married about 1637, and daughter of Great Migration immigrant JOHN NEWGATE (GM 1633). Elizabeth’s sister, Sarah Newgate, married John Oliver’s brother, PETER OLIVER (EF). Edward Jackson had children by both of his wives, and Elizabeth had children by both of her husbands.

The problem compounds with succeeding generations. John and Elizabeth Oliver’s son Thomas Oliver married Grace Prentice, whose brother, John Prentice, married Edward and Elizabeth Jackson’s daughter (and half-sister to Thomas), Elizabeth Jackson. Grace and John Prentice are children of Thomas and Grace (_____) Prentice of Cambridge. What doesn’t show up in this sketch is that Grace and John Prentice had a brother Thomas Prentice, whose son Capt. Thomas Prentice married Elizabeth Jackson, daughter of Edward Jackson, Jr.

To put the icing on the cake, Rebecca Jackson, a child of Edward Jackson and his first wife, Frances, married a Thomas Prentice, often mixed up with the above Thomases. Some hair-pulling research for this Edward Jackson sketch, however, has shown us that Rebecca’s Thomas Prentice (often listed as 2nd) was a completely different individual, most probably the son of ROBERT PRENTICE (GM 1639) (more details will be included with the Jackson sketch).

The Olivers, Jacksons, and Prentices were part of a wealthy cluster of socially and politically connected families in Boston and Cambridge. They demonstrate that studying families in groups can be advantageous for many genealogical problems—for example, finding the surname of an unknown wife. Here are a few examples of how one might use genealogical clusters when researching a mysterious wife, “Ruth.”

Kinship clusters: Look at the spouses of Ruth’s husbands’ siblings. Brothers marrying sisters was common in large families. Do any of the wives or husbands have sisters named Ruth? Did any of the wives’ fathers leave a will that might name his other daughters by their married names?

Geographic clusters: Look at land and town records for the husband’s family. What families were abutters? From whom did the family buy and sell land? Who witnessed the deeds?

Economic and social clusters: Was Ruth’s husband’s family rich or poor? Romantic novels aside, it is true that grooms usually chose wives (or had wives chosen for them) from families of the same, if not better, economic, social, and political status. What families were they affiliated with in town, county, or colony records? For poor families with no property, investigate court records. If someone was arrested, who posted bail or paid a fine for them? Who testified for or against them in court?

Religious clusters: To what denomination did Ruth’s husband’s family belong? Are there any members of the same church with unattached daughters named Ruth? Perhaps was someone dismissed from a church for marrying out of the religion?

You will undoubtedly identify different sets of clusters that apply to different families, but always keep clusters in mind as you consider the extended population around a family in your research.



EF designates an individual treated in Early New England Families Study ProjectGM designates an individual treated in The Great Migration Study Project.

About Alicia Crane Williams

Alicia Crane Williams, FASG, Lead Genealogist of Early Families of New England Study Project, has compiled and edited numerous important genealogical publications including The Mayflower Descendant and the Alden Family “Silver Book” Five Generations project of the Mayflower Society. Most recently, she is the author of the 2017 edition of The Babson Genealogy, 1606-2017, Descendants of Thomas and Isabel Babson who first arrived in Salem, Massachusetts, in 1637. Alicia has served as Historian of the Massachusetts Society of Mayflower Descendants, Assistant Historian General at the General Society of Mayflower Descendants, and as Genealogist of the Alden Kindred of America. She earned a bachelor’s degree from the University of Connecticut and a master’s degree in History from Northeastern University.

26 thoughts on “Genealogical Clusters

  1. Thanks for the focus on an interesting area of genealogical study. I have recently worked on material for a single company in a Civil War Regiment. The cluster of relationships among enlistees, 10 of whom were interrelated and lived within 2 miles of each other in the rural community of Argyle, New York, encompassed all the forms you discussed. In such communities, families intermarried, went to school together, worked together, worshiped together, and went to war together. In this case, two of the neighboring enlistees, John Dixon Williams and Charles Evans Reid, married each others siblings, respectively, Jane Elizabeth Reid and Esther Jane Williams, in the weeks before muster. Three brothers and five cousins accounted for the other eight.
    One observation from this microcosm of the time, is that the incidence of such clusters was lessened in future generations (at least in the north-eastern states), as expansion of the country and improved transportation networks following the civil war brought migration to the west, and, with it, more family diversification.

  2. You are my hands down favorite on this blog. Your research insights are the absolute best. Thank you for your hard work and the clarity with which you write about your research.

  3. Great checklist for sorting out these hair-pulling same-name records. My Cozzens family in Sherborn MA had this pattern as well. I’ve resorted to adding a suffix, “of _____town” to keep my own head straight among all the Abrahams, Isaacs, and Josephs.

  4. “Edward was a post- Great Migration Begins immigrant, arriving in New England in 1642 or 13”. I always thought that the Great Migration lasted at least thru the 1640s. But I see that you call 1642/3 as post-migration. Are there established dates for when the Great Migration occured and how many people immigrated within each part of the GM? What about someone who came in the 1660? Are they post-post migration?

    1. The official use of “Great Migration” was established by Robert Charles Anderson in his Great Migration series. He has many articles about why he chose the years 1620-1640 in his “Great Migration Newsletter,” which is also available on the americanancestors database. That newsletter, published over 25 years, is an excellent learning tool for early New England sources. Highly recommended to everyone.

  5. Hello Alicia, We have the same situation in my husband’s family Lawrence. They lived on the Caribbean island of St. Martin as far back as the late 1700’s or earlier. They intermarried since it was a small island where white families were not numerous. Couins marrying cousins happened through several generations.This makes it very difficult to create a legible family chart.

  6. I’m trying to figure out the Chandler/Abbot families of New England in the early to mid 1600’s

    1. Cherri, Since there were 6 Chandler Great Migration immigrants and 5 Abbots, you have your work cut out for you. If you haven’t already consulted the sources listed in “The Great Migration Directory” by Robert Charles Anderson. This is not online, unfortunately, but it is an extremely important reference to have. Costs a lot, but if you can team up with others and share the book, you will all benefit.

  7. Alicia,
    I seek out and hang on tight to your posts! Always well worth my time and complete engagement. Thank you for all you do,
    Judith Harper

  8. Oh, welcome news that you’re doing Edward Jackson in EF. A number of your EF sketches have been very helpful, thank you. Jackson and the rest of the cluster are interesting – as is Hannah Jackson (Ward)’s father-in-law in Marlborough.

  9. I have SO many of those!! A few weeks ago I thought I would reorganize my binders by family rather than by generation. I gave up on that idea today and am going back to generation. I dread putting everything back the way I had it but it will also give me a chance to update stuff that is pretty old. And IF I’m smart 😉 I’ll read what I have. So often once I’ve done a line I never reread it again. Many times I have information that I forgot I had or that didn’t make sense at the time I saw it. I have thrown away about 2 reams of paper and a corresponding amount of printer ink BUT I have replaced it with new information, fresh paper, and printer ink!

    1. Toni, boy, can I relate to that! I have reorganized and restarted the family genealogy multiple times and still don’t have a perfect answer except “just sit down and do it.” Good luck.

  10. Thanks for your historical work, Alicia Crane Williams! I’m hoping to reach you about your Crane family work, related to my current research. Would you be able to send me an email? I would appreciate it much! Etta Madden, Missouri State University

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