Stidham/Stedman Surnames DNA Project
The study (initially under the surname Steadham) began back in the Fall of 2000. It was among the first surname projects conducted at Family Tree DNA, preceeded only by the Mumma Surname Project (Facts & Genes From Family Tree DNA, June 2, 2003, Volume 2, Issue 5; and Timeline: Pioneer surname projects before 2002). In 2004, the Stedman surname (all variations) was added to the project, as the Stidham and Stedman surnames had become interchangeable for many families throughout the years.
The initial focus of the study was to determine which Stidhams (all spellings) were genetically descended from Timen Stiddem, and conversely, which may have instead descended from the Scottish immigrant, John Steedman (1715-1795), many of whom now spell their surname as Stidham, Stedham, or Steadham.
The results thus far have proven that many of the Stidham* participants do genetically descend from three of Timen's five sons. They have also shown that several do not—those descending from Samuel  Stidham. However, results have also proven that Samuel  Stidham was NOT a descendant of the Scot, John Steedman.
In 2009, a 67-marker match was made between a Samuel  Stidham descendant and a man bearing the surname CATLEDGE. This has the potential to be a huge discovery for this line of the Stidhams, as it could prove to be their direct male lineage, one descending from a John Cartledge (b. before 1550, England) whose great-grandson, Edmund Cartledge III (b. 14 Feb 1639, p. Dronfield, Derby, England; d. 26 Feb 1703, p. Darby, Chester, PA) had immigrated to America as one of Willam Penn's English settlers by 1682. Thus far, only one man with this surname has tested. If over time, several other men bearing this same surname test with the same results (showing he's not an outlier within this surname), it would prove he carries the dominant Cartledge genetic signature. It could also prove to be the answer for the Samuel  Stidhams in their quest to find their true Y-DNA line. Much more testing needs to be done in this area before definitive relationships can be established.
In 2004, a monumental surprise result proved that one of the presumed "rock solid" descendants of John Steedman was actually a descendant of the Swede, Timen Stiddem instead. Here is a link to some thoughts about this from John Lisle, Co-Administrator of the project, managing the Stedman surames.
Here is the link to join the project. You should order at a minimum, the Y-DNA37 test (currently $149). If possible, the Y-DNA67 test would yield the most refined results available (currently $248). Only open to males bearing the Stidham or Stedman (or some variation) surnames, or who can trace a father-to-son biological link to such a male. For women, a brother, father, uncle or male cousin would need to participate on their behalf.
Alternatively, any descendant of Timen Stiddem can join the project using the Family Finder test, which tests a person's autosomal chromosomes inherited from both their mothers and fathers.
We welcome your comments and questions.
Richard Steadham, Co-Group Administrator of the Stidham/Stedman Surnames Project.
John Lisle, Webmaster, Stedman Family Organization, a website for family history and genealogy research of the Stedman, Steadman and Steedman Families, and Co-Group Administrator of the Stidham/Stedman Surnames Project.
Here is a link to the Stidham/Stedman Surnames Project at Family Tree DNA.