I've been revising my chapter on Mart Rider in the Other Noted Guerrillas book with the idea of perhaps publishing a second edition. (The print version of the book is currently out of print.) If I do, the new chapter will combine the activities of Mart and Jim Rider (simply because the two men have been discussed together so much), but it will focus more on Jim than on Mart, since Jim was, in fact, the more active of the two, at least as a guerrilla. As to the parentage of Jim Rider, this question continues to be a bit of a mystery. One researcher (who wrote his master's thesis in history for MU about the Rider family, et al.) has suggested Jim Rider was the son of James M. Rider of Macon County. However, James M. Rider's son, James Henry Rider (who often went by Henry) was in the regular Confederate Army and never a guerrilla as far as I know. I think Tabitha or Talitha Rider, Jim's wife, was correct in saying that George Rider of Saline was Jim's uncle. I find it hard to believe a woman would be so uninformed about her husband's family that she would not know who his father was. However, if Tabitha/Talitha was correct, the question arises as to how do we account for the James Rider, 13 years old in the 1850 census, living in the household of George Rider of Saline. And how do we account for George Rider of Saline saying (as recounted in Provost Marshals papers, that his son had "gone to the bush" or words to that effect? Did James Rider have a cousin also named James, or was James living with his uncle at the time of the 1850 census? Or was Tabitha/Talitha, in fact, mistaken in the family relationship. The same researcher who identified James M. Rider of Macon as the father of guerrilla Jim Rider also said that this James M. Rider and the George Rider of Saline were brothers and that there was also a third brother named John who lived near George in Saline. I question this researcher's conclusion that James M. of Macon was a brother of George of Saline, since James M. apparently came directly to Mo. from his birth state of Delaware, while George was born in VA and lived in Tenn. prior to coming to Mo. Also, I can't seem to find a John Rider who might be a brother to George in any Saline County census records, but Tabitha/Talitha seems to confirm that such a person did exist. If there was, indeed, a John Rider living in Saline at the time of the CW, I would think he would be a very good candidate to be father of Jim. Capt. Eli Crandall says in one of his OR reports that Jim Rider had gone into Saline where "his father" lived. But was Crandall talking about George or John?
There apparently is no close relation, as I had thought at the time I wrote the 1st edition, between Mart Rider and the George Rider family of Saline. There may be some connection, since both families came to Mo. from Tenn. It's possible, for instance, that the Saline George Rider was a cousin to Mart's father, John Rider, Jr., but even that is in doubt. On the other hand, the George Rider of 1860 Jackson County census was, in fact, a brother of Mart Rider's father.
By the way, I've got a new book on the Battle of Lexington coming out from The History Press, probably about three months from now. Unlike with some of my other books for The History Press, I've taken a more scholarly approach for this one, with end notes that cite sources, etc.