Parents of Judith (c. 1712-aft. 1767), wife of John Williamson, Sr., (c. 1705-1757)

Parents of Judith (c. 1712-aft. 1767), wife of John Williamson, Sr., (c. 1705-1757)

by Shawn Henry Potter and Lois Carol Potter
renatuspress.com

1. Introduction:

Family-like associations, chronology, location, and onomastic patterns suggest that Judith (c. 1712-aft. 1767), wife of John Williamson, Sr., (c. 1705-1757) of Henrico County, Virginia, was a daughter of Stephen Pettus III (c. 1685-1759) and Mary Dabney (c. 1692-1736). (See Appendix 1.) To test this theory, we compared the autosomal DNA of 10 descendants of Stephen Pettus III and Mary Dabney with the autosomal DNA of 10 descendants of Judith and John Williamson, Sr., to discover whether descendants of Judith and John Williamson, Sr., inherited matching segments of autosomal DNA 5cM+ in length that are shared with descendants of Stephen Pettus III and Mary Dabney. We made these comparisons using the tool on GEDmatch (https://www.gedmatch.com) called “One-to-One Autosomal DNA Comparison.”

2. Results:

Comparisons between autosomal DNA inherited by 10 descendants of Judith and John Williamson, Sr., and autosomal DNA inherited by 10 descendants of Stephen Pettus III and Mary Dabney produced the following results.

Comparisons between autosomal DNA of descendants of Stephen Pettus III and Mary Dabney and descendants of Judith and John Williamson, Sr., produced these results.

Note: We refer to autosomal DNA kits by their GEDmatch designations. Kits listed on the left side of the table belong to descendants of Stephen Pettus III and Mary Dabney, whereas kits listed along the top of the table belong to descendants of Judith and John Williamson, Sr. Every kit, except kits of siblings M230922 and M211057, is associated with a user-produced GEDCOM available on the GEDmatch website. Kits of siblings M230922 and M211057 are associated with a user-produced tree of ancestors on Ancestry.com. Examination of Stephen Pettus III and Mary Dabney descendant trees and Judith and John Williamson, Sr., descendant trees revealed no shared ancestry between Judith and John Williamson, Sr., and descendants and Stephen Pettus III and Mary Dabney descendants except Stephen Pettus III and Mary Dabney.

These comparisons revealed that every one of the 10 descendants of Judith and John Williamson, Sr., inherited matching autosomal DNA segments 5cM+ in length with from 4 to 7 of the 10 descendants of Stephen Pettus III and Mary Dabney. (See Appendix 2.) This overall average match rate equals 54%.

Furthermore, twelve of the matching autosomal DNA segments were inherited by three or more Stephen Pettus III-Mary Dabney / Judith-John Williamson, Sr., pairs. This is significant, because triangulated matching segments are more likely to be Identical-by-Descent.

3. Discussion:

GEDCOMs of descendants of Stephen Pettus III and Mary Dabney show Stephen Pettus III and Mary Dabney, on average, as 9th generation ancestors; and GEDCOMs of descendants of Judith and John Williamson, Sr., show Judith and John Williamson, Sr., on average, as 8th generation ancestors. This means that, if Judith were a daughter of Stephen Pettus III and Mary Dabney, descendants of Stephen Pettus III and Mary Dabney and descendants of Judith and John Williamson, Sr., would be 8th cousins. Recent research reveals that 8th cousins are expected to share autosomal DNA segments 5cM or less in length.[1]

By comparing autosomal DNA of multiple descendants of Judith and John Williamson, Sr., with autosomal DNA of multiple descendants of Stephen Pettus III and Mary Dabney, we filtered out potential Identical-by-State random matches. That is to say, if Judith were not a daughter of Stephen Pettus III and Mary Dabney, we would expect only about 1% to 2% of the 100 comparisons to result in shared autosomal DNA segments 5cM+ in length. However, 54% of the 100 comparisons resulted in shared autosomal DNA segments 5cM+ in length. This result is over 50 times the expected rate of Identical-by-State random matches, demonstrating that these matching segments must be Identical-by-Descent.

4. Conclusion:

These results corroborate conclusions from circumstantial evidence, including family-like associations, chronology, location, and onomastic patterns, regarding the parentage of Judith, wife of John Williamson, Sr. This autosomal DNA evidence demonstrates to a level of certainty beyond a reasonable doubt that Judith, wife of John Williamson, Sr., was a biological daughter of Stephen Pettus III and Mary Dabney.

Furthermore, a significant number of the matching autosomal DNA segments contain Native American ethnicity. (See Appendix 3.) This additional finding supports the research of William L. Deyo regarding the Native American descent of Stephen Pettus III from Pocahontas and Kocoum.

Appendix 1

Family-like associations, chronology, location, and onomastic patterns suggest that Judith (c. 1712-aft. 1767), wife of John Williamson, Sr., (c. 1705-1757) of Henrico County, Virginia, was a daughter of Stephen Pettus III (c. 1685-1759) and Mary Dabney (c. 1692-1736).[2]

Family-like associations and onomastic evidence suggest these relationships.

Note: For information about the ancestors of Stephen Pettus III and Mary Dabney, see William L. Deyo, Pocahontas and Kocoum Their Early Descendants and Indian Ancestors (Colonial Beach, Virginia: Dejoux Publications, 2025), 19, 25-26, 30, 41, 55, and 147. https://billdeyo.com/

1. Dabney Pettus (c. 1724-1788), son of Stephen Pettus III (c. 1685-1759) and Mary Dabney (c. 1692-1737), served as surety for orphan Mary Williamson (c. 1752-1820), granddaughter of John Williamson, Sr., (c. 1705-1757) and Judith Pettus (c. 1712-aft. 1767) at a Henrico County, Virginia, February Court, 1765.

2. Judith Lancaster (1776-1856) and William Allen Lancaster, Jr. (1772-1860), son of William Allen Lancaster, Sr. (1736-1778) and Judith Williamson (c. 1748-1783), and grandson John Williamson, Sr., (c. 1705-1757) and Judith Pettus (c. 1712-aft. 1767), named a son Dabney Lancaster (1806-1893).

3. Mary Williamson (c. 1772-1827) – descendant of a different Williamson branch – and Samuel Lancaster (c. 1770-1809), son of William Allen Lancaster, Sr. (1736-1778) and Judith Williamson (c. 1748-1783), and grandson of John Williamson, Sr., (c. 1705-1757) and Judith Pettus (c. 1712-aft. 1767), named a son George Dabney Lancaster (c. 1798-1853).

4. William Miller (c. 1740-bef. 1793) and Elizabeth Williamson (c. 1744-1771), daughter of John Williamson, Sr., (c. 1705-1757) and Judith Pettus (c. 1712-aft. 1767), named a son Dabney Miller (c. 1766-1820).

5. Samuel Williamson (c. 1734-1800), son of John Williamson, Sr., (c. 1705-1757) and Judith Pettus (c. 1712-aft.  1767), married his cousin Mary Young (c. 1736-aft 1799), daughter of Judith Dabney (c. 1706-1783) and James Young (c. 1703-1772), and named a son Dabney Williamson (c. 1761-1848).

Appendix 2

Autosomal DNA Matches. Note: “TM” signifies triangulated matches. Also Note: T070972 and T084995 were siblings, and M230922 and M211057 were siblings.

Data from autosomal DNA comparisons, including triangulated matches.

Appendix 3

Native American ethnicity in the following matching autosomal DNA segments is illustrated with the tool on GEDmatch (https://www.gedmatch.com) called “Admixture (heritage).” The presence of Native American ethnicity in these matching segments of autosomal DNA supports the research of William L. Deyo regarding the Native American descent of Stephen Pettus III from Pocahontas and Kocoum.

Comparing Kit CZ643805C1 and Kit RZ9133442 (Triangulated Matching Segment)

Matching segment of autosomal DNA containing Native American ethnicity on chromosome 14.

Comparing Kit A861433 and Kit T235598

Matching segment of autosomal DNA containing Native American ethnicity on chromosome 10.

Comparing Kit M230922 and Kit M104041

Matching segment of autosomal DNA containing Native American ethnicity on chromosome 15.

Comparing Kit A608655 and Kit ML9638568 (Triangulated Matching Segment)

A second matching segment of autosomal DNA containing Native American ethnicity on chromosome 15.

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[1] Amy L. Williams, “The Rate of Identical-by-Descent Segment Sharing between Close and Distant Relatives,” in PubMed Central, 30 Jun 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC12324479/ “The average amount of DNA 10th degree relatives are expected to share is 210 of their genomes, or about 6.5 cM in the genetic maps we used (sex averaged autosomal length 3,346 cM; total diploid length 6,693 cM). This expectation includes relatives that share zero IBD and matches our observations (mean 6.5 cM shared considering all 4C1R). Yet conditional on sharing at least one segment, on average 4C1R share 12.7 cM of DNA, meaning that these 10th degree relatives have sharing closer to the expectation for 9th degree relatives. An even more extreme case is the 15th degree 7C who, conditional on carrying IBD, share an average of 6.34 cM, which is roughly in line with 10th degree relative sharing. This shift in IBD amounts for relatives that share at least one IBD segment can lead to substantial bias in relatedness estimates, as Jewett recently pointed out and developed models to correct for.” Note: Using this terminology, 8th cousins would be 16th degree relatives.

[2] For information about these individuals and their family relations see the following contemporary records.

(1) Dabney Family of Early Virginia, Cornelius Dabney (b. 1630) and His Descendants, https://www.dabney-early-virginia.info/getperson.php?personID=I212&tree=Dabney&sitever=standard, accessed 1 Jan 2026.

(2) See also July 7, 1763. Samuel Allen and Elizabeth Allen of Lunenburg deed to Peter Elmore of Henrico for £150, 160 acres in Henrico purchased of John Williamson, deceased, lying between the lands of Dabney Pettus, Thomas Conway, and James Browning. Recorded August 1, 1763. Edward P. Valentine Papers, vol. 1, p. 807.

(3) See also April Court, 1764. Petition of Judith Williamson, widow of John Williamson [Sr.], for her dower in lands of the dec’d, referred to next court. Henrico County, Virginia, Records, p. 217.

(4) See also October Court, 1767. On petition of Judith Williamson for her dower in lands of her dec’d husband, John Williamson, it is ordered that Benjamin Duval, gent., surveyor of this county, lay off her dower in three lots in Richmond town. Henrico County, Virginia, Records, p. 177.

(5) See also February 19, 1771. John Sutton Farrar and Susannah [daughter of deceased], his wife, Samuel Williamson [son of deceased], Allen Williamson [son of deceased], Thomas Williamson [son of deceased], James Browning and Ann [daughter of deceased], his wife, William Miller and Elizabeth [daughter of deceased], his wife, Groves Harding and Sarah [daughter of deceased], his wife, William Allen Lankaster and Judith [daughter of deceased], his wife, and Lucy Williamson [daughter of deceased], residual legatees under the will of John Williamson, dec’d, to Charles Snead of Henrico County, for £30, 170 acres in Henrico on Georges Branch. Witnessed: Daniel Kelly, Robert Snead. Recorded August 5, 1771. Henrico County, Virginia, Records, p. 293.

(6) See also July Court, 1762. Will of John Williamson [Jr.] presented by Robert and Samuel Williamson [brothers of deceased], the executors and proved by witnesses and entered bond with William Lewis and Thomas Wilkinson. Isaac Winston, Thomas Williamson [brother of deceased], Henry Stokes, and Matthew Hobson to appraise. Henrico County, Virginia, Records, p. 614.

(7) See also October Court, 1767. Robert and Samuel Williamson [sons of John Sr. and brothers of John Jr.], executors of John Williamson, Sr., and John Williamson, Jr., are to produce the persons ordered to settle the estate and return the December Court. (Henrico County, Virginia, Records, p. 177. Henrico Mixed Records, vols 2-3, 1766-1852, images 262-263, Samuel Williamson Will, signed 13 Jun 1799, proven 3 Dec 1799, pp. 494-495. Henrico County, Virginia, February Court, 1765. Mary Williamson, orphan of John Williamson [Jr.], chose Groves Harding [uncle of Mary, husband of Sarah Williamson] her guardian; Dabney Pettus and Turner Southall, securities. Henrico County, Virginia, Records, p. 417. [Note: Mary Williamson married Benjamin Lacy about 1769, and died in Goochland County, Virginia, in February 1820.]

(8) See also Prince Edward County, Virginia, Marriage Bond. 15 Aug 1797. William Lancaster and Judy Lancaster, dau. of Nathaniel Lancaster who is surety. Catherine Lindsay Knorr, Marriage Bonds and Ministers’ Returns of Prince Edward County, Virginia 1754-1810 (Published by Catherine Lindsay Knorr, 1950), p. 45.

(9) See also Smith County, Tennessee. Signed: 25 Aug 1858, Proven: Jan 1860, p. 52. Will of William Allen Lancaster. Heirs: Nathaniel Lancaster, Samuel Lancaster, James Lancaster, Dabney Lancaster, Nancy wife of John Powel, Polly wife of Stephen Lancaster, Frances Bradley, Elizabeth Rich, Elizabeth Corkey, William Robert Corkey. Witnesses: John S. Gill, William J. Johnson, James W. Johnson. Executors: E.A. Wright, J.R. Smith. Smith County, Tennessee, Will Records, Vol. 1-3, 7-8, 1803-1896. Image 116, p. 109.

(10) See also Henrico County, Virginia, Marriage Bonds, 1782-1853. Samuel Lancaster to Mary Williamson. William Williamson, surety, 12 Dec 1792. Image 101, p. 97. Henrico County, Virginia, Marriage Bonds, 1782-1853. Samuel Lancaster to Mary Williamson. William Williamson, surety, 12 Dec 1792. Image 101, p. 97.

(11) See also Amelia County, Virginia, Marriage Records. Elizabeth Petty Bentley, Virginia Marriage Records from the Virginia Magazine of History and Biography, and William and Mary College Quarterly, and Tyler’s Quarterly (Baltimore, MD: Genealogical Publishing Co., Inc., 1984), Image 68, p. 57. 12 Dec 1791. Dabney Miller and Polly Crowder, d. of William.

(12) See also Grave of George Dabney Lancaster. https://www.findagrave.com/memorial/37758087/george_dabney-lancaster.