I'm having trouble placing your Jacob. According to Martin Kershners will dated Nov. 30, 1769, he names wife Margretha and oldest son Martin, second and third sons David and George and then later refers to youngest son George. No mention of a Jacob. He also refers to grandchildren Joseph, Martin, and John Baum (children of daughter Magdalena who married Jacob Baum) and to the two daughters of George Ritinawer, dcd., Margrath and Elizabeth (George Ritinawer being the husband of daughter Margaretta). He also directs his executor to make lawful deeds to John and George Kirshner and George Kirshner Senr. and Jacob Kirshner but none of these are refered to as sons. He names Jonathan Hagar (Jr) and son Martin as executors. I have seen genealogies that claimed John Martin had a brother John who had a son Jacob but I cannot verify that. I also do not know who the children of John Martin's brother George are or who the children of his brother Jacob are. On the 1783 tax list for Washington Co., MD are Martin Jr., David, two Georges, two Jonathans, Jacob, and Philip. Most of my info comes from compiled records such as "Western Maryland Genealogy" and "Washington Co., Maryland Church Records of the 18th Century 1768-1800". Also some comes from "Kershner Kinfolk" aperiodical began in 1982, published by The Kershner Family Association. I don't knkow how long it was published as I have only Vol. 1, No. 2. It mentions a book "The Kershner Families of Maryland 1731-1977" but I have never seen this book. I am not the expert on this family. I have a lot of info on them but have as many questions as answers. I have many photocopied pages that I don't know the name of the book they came from that I collected many years ago. I have spent many hours searching through census records trying to run down branches of the family although I still don't know where many of them belong. There are many Kershners who served as patriots of the Revolution, several who served in Capt. Martin Kershner's Company, 32 Battalion, Maryland Militia. My David served as First Sergeant and later as Second Lieutenant in this company under his brother Martin. A Jacob, a John, a Jonathan, and a Philip also served in this company from Washington Co., MD. A George Kershner served in Capt. Adam Ott's company, Select Militia. A Michael Kershner enlisted in the German Regiment, Continental Line in Baltimore, MD. You may see posts by my brother Richard Bench and he probably knows more than I on this line.