Saturday, February 7, 2026

The Case of the Missing Mothers: 52 Ancestors 2026 Prompt “A Theory in Progress”

 

Thomas Buckminster’s Two Wives and Nine Children: Which Wife Gave Birth to Which Children?

Thomas Buckminster: 1593-1656 (Maternal 9th Great-Grandfather)
Margaret Cossen: 1597-1629 (Maternal 9th Great-Grandmother)
Joanna Robinson: 1597-1676 (Wife No. 2)
 

I’ve been making use of the new Ancestry feature, the Tree Checker program. It helps me identify errors in my tree, and equally important, which individuals in the tree lack sources and records. I discovered that when I originally added the Thomas Buckminster family (my maternal 9th Great-Grandfather) to my family tree, I had found sources verifying basic birth, death and marriage information for my direct ancestor, Thomas’ son Zachariah Buckminster. However, I had failed to do the same for Zachariah’s eight siblings. I hadn’t even verified which of Thomas’ two wives had given birth to which child. Ancestry’s Tree Checker flagged all of Zachariah’s siblings as “people with no sources”. I decided it was time to rectify this omission.

My 9th Great Grandfather Thomas Buckminster was born in England in 1593, and immigrated to the American Colonies around 1630 following the death of his first wife, Margaret Cossin, in 1629. He settled in the Muddy River area of Suffolk County, Massachusetts and married Joanna Robinson.

Muddy River on a 1777 map of Brookline area near Boston.

I had some theories about his nine children’s parentage. Other Ancestry trees tended to show that second wife Joanna was the mother of at least six or seven of the nine children. I believed that first wife Margaret was actually the mother of not only my 8th Great Grandfather Zachariah, but four or five of his siblings as well. I needed to see if I could verify that theory.

Thomas Buckminster’s first wife died in 1629. Obviously, any children born after that date were the children of second wife Joanna Robinson. So my first job was to find birth records or documents that verified the birth year of the eight siblings.

Muddy River today

I located a transcription of Thomas’ will, made out in 1656 shortly before his death. His heirs included the following children: Zackery (Zachariah); daughters Elizabeth Spowell, Mary Stevens, Dorcas Corben, and Sarah Buckminster, and sons Thomas, Joseph and Jabesh (Jabez). The will offered me some clues about which children were the progeny of second wife Joanna. Thomas noted that sons Thomas, Joseph and Jabesh, and daughter Sarah were all minors under the age of twenty-one. The will instructs that they receive forty shillings “each to be paid when severally ‘one & Twenty years of Age.’” That means that each of them were born after 1636, so could not have been the children of Margaret, who died in 1629. All four, therefore, were Joanna’s children.

But what about the other children? I found birth and probate records for Thomas’ son, Lawrence Buckminster. He was born in England in 1619, so his mother must have been Margaret Cossen. Lawrence was Thomas’ eldest son, six years older than my ancestor Zachariah. Lawrence died at sea in 1645, thus preceding Thomas in death.

As for daughter Elizabeth, I found a baptism record for her dated August 17, 1628. The baptism took place in Sempringham, Lincolnshire, England. This is the same parish where her brothers Lawrence and Zachary were baptized. Although I have found no actual birth record, she was obviously born before August 17, 1628. This confirms she was Margaret Cossen’s daughter. Elizabeth accompanied her father to Massachusetts and married William Spowell in 1652. I have been unable to find a death record for her.

As for daughter Dorcas, I have been unable to find any birth or baptism records for her. Her headstone states that she died January 22, 1721 at the age of 92. That would mean she was born in 1629 when Thomas Buckminster was still in England, meaning Dorcas was Margaret’s last child. Perhaps Dorcas’ birth led to her mother’s death, which occurred in 1629.



Thomas Buckminster’s ninth child was daughter Mary. I was unable to find any birth records for her. However, court records related to her father’s estate hint that she was the daughter of second wife Joanna Robinson Buckminster. Following Joanna’s remarriage, several of Thomas' children petitioned the court that administration of the estate be transferred from Thomas’ widow Joanna to them as Thomas’ children.

“On 27 July 1669, "Jabesh Buckminster, Mary Stevens, Dorcas Corbin, and Sarah Lawrence, son and daughters of Thomas Buckminster sometimes of Muddy River in Boston deceased," petitioned the court to be appointed administrators to their father's estate, referring to the marriage of their mother, Joanna Buckmaster, to Edward Garfield. Among the many depositions collected during the consideration of this petition was one from "Henry Stevens" who "affirmed in court 27 July 16[70] its four years come August next since his mo[ther]in] law Joanna Garfeild died."

Henry Steven’s reference to Joanna as his mother-in-law would suggest that his wife Mary was Joanna’s daughter. Mary’s uncomfirmed birthdate from several Ancestry trees was 1632, which followed the estimated 1630-31 date of Thomas’ marriage to Joanna. Henry and Mary also named one of their daughters “Joanna”. While these things suggest Joanna is Mary’s mother, without any actual documentary evidence, Mary’s parentage will remain theoretical.

So my original theory was only partially correct. I was able to confirm that three of my 8th great grandfather’s siblings were his full siblings—the children of Thomas Buckminster’s first wife Margaret Cossen. However, I confirmed that four other siblings were the children of Thomas Buckminster’s second wife, Joanna, and that last sibling is probably also her child. I had theorized that at least one and possibly two of those siblings were Margaret Cossen’s children.

I need to continue to research this family to see if there are any additional records that can clarify family relationships. But at least the entire Buckminster family now has records attached to them, and will no longer appear on Tree Checker as “people with no sources.”

Sources:

Photo of Muddy River. Wikimedia Commons. John Stephen Dwyer, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons https://commons.wikimedia.org/wiki/File:Olmsted-Park-Muddy-River.jpg

Henry Pelham’s 1777 Map of Boston area.

Photo of Dorcas Buckminster Corbin headstone. Gravestones of the First Corbins in America.