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From the Corson Cousins newsletter, January 2006

Corson Surname DNA Project

Since last issue’s report, the project gained three participants with the surnames Courson, Courser, and DeCoursey.

The Courson participant descends from James Courson (b. ca. 1762 in Lancaster Co., South Carolina), who served as a private in the Revolutionary War.  Descendants of James currently live in states such as Alabama, Georgia, and Texas, and they may be related to the Coursons who settled in the “Wiregrass” region of southern Georgia and northern Florida.  The participant’s DNA results do not match those of any other participant in the project, which confirms that he does not descend from the two Divisions whose genetic signature we've been able to estimate (Divisions I and II).  Based on his genetic signature, he appears to belong to a haplogroup (genetic group) currently called “J2”.  This indicates that James Courson’s male-line ancestors lived in the Mediterranean region thousands of years ago.  If James came from western Europe, then one of his male-line ancestors likely migrated there within the past 5000 years.  We are looking for other “southern” Coursons who would be interested in participating in the project.

The Courser participant joined the project to test the hypothesis that he descends in a direct male line from Benjamin Fletcher Corsse (1692-1770), son of Division II progenitor Jan Corzen (ca. 1649-1703).  According to his test results, his genetic signature matches those of the two Corsa/Corson descendants of Jan Corszen already tested.  In fact, it matches theirs on all 43 markers examined.  This result supports the paper-trail genealogy that documents Captain Isaac Corser/Corsa (c.1737-c.1840) as a son of Benjamin Fletcher Corsse.  After the Revolutionary War, Isaac and his son John Courser (1765-1847), as Loyalists, emigrated from New York to Nova Scotia, settling later in Prince William, New Brunswick.  Another son of Isaac’s, Andrew Corsa (1762-1852), an ancestor of the project’s Corsa participant, remained in New York.  Division II descendants belong to haplogroup I1a, a haplogroup that occurs most frequently in northern Europe and Scandinavia.

The DeCoursey participant documents his descent from William DeCoursey (bef. 1720-1788) from Bensalem Twp., Bucks Co., Pennsylvania.  Some have hypothesized that the Bucks County DeCourseys descended from Division III's Benjamin Corssen (1686-1740).  At least for this participant, the DNA data do not support this hypothesis, since the participant’s genetic signature differs greatly from Benjamin's (which was estimated from those of two descendants of Benjamin).  We don't yet know, however, whether this DeCoursey participant carries the genetic signature of all Bucks County DeCourseys.  Consequently, we’re working to contact distant relatives of his for testing.  The DeCoursey participant belongs to haplogroup R1b, the most common haplogroup in Europe.

Corson project participation graph

2005 - Year in Review

In 2005 the project gained 15 of its 20 participants (Fig. 1), with the following surnames: Colson (2), Corsa (1), Corson (7), Courser (1), Courson (1), DeCoursey (1), and Vroom (2).  Based on their results and documented genealogies, we were able to establish the genetic signatures of the following ancestors: 

 One participant discovered that his brick-walled ancestor, William Corson (bef. 1765- aft. 1823), had a common ancestry with two Corson participants who trace their descent from Division IV.  As just reported, another participant confirmed that his ancestor John Courser (1765-1847) had a common ancestry with one Corson and one Corsa participant who trace their descent from Division II.  In the coming year, our main priorities will be to determine the ancestral genetic signatures for Divisions III, IV, and VII.  We’ll also aim to establish ancestral signatures for the surnames Courson and DeCoursey.  

DNA Project Newsletter Available

 If you would like to receive more frequent news about the DNA project, you can subscribe to the electronic newsletter that I send out as an e-mail message each month.  You can read past issues of the newsletter, browse male-line lineages of current participants, and see test results and interpretation at the project website:

Recommended Reading

 If you’d like to learn more about the uses of DNA for genealogy, a good introductory book is Trace Your Roots with DNA : Using Genetic Tests to Explore Your Family Tree, by Megan Smolyenak and Ann Turner.  It describes how DNA tests work and what they can and cannot tell you about your male-line or female-line ancestry. Megan Smolyenak recently wrote an interesting article for titled, “Have You Already Been DNA-Tested?”.  It emphasizes that one person’s Y-chromosome DNA represents not only that person, but also all male-line relatives who descended from that person's earliest known male-line ancestor.  If you have Internet access, you can read it at