I have made a 'score' years (20+) researching Daugherty/Dougherty lines in PA/VA/MD/NC/TN.
There were no descendants from William and Ruth Towson Daugherty named Samuel then to a Joseph. I can unequivocally speak to that. However, that said, your names follow a pattern in the Michael Mor Dougherty line that settled in PA. moved into the Beverly/Borden Grants area of Rockbridge Co., VA in the mid 1700's where William and his brothers James and John passed through and on into SW VA in Scott/Tazwell/Russell Counties between 1790 and 1902. These 4 siblings migrated to America between 1785 and 1795. While many of the Michael Mor line remained in PA while other branches are scattered into the Shenandoah Valley and on into Kentucky and by the 1840's on to the West Coast.
You mention PA in your post, if you have any dates for Samuel and Joseph, please let me know, I may be able to help.
Through Clann o'Dochartaigh, we have been able to finally establish a link between the Michael Mor Dougherty line and my James-John-William-Nancy line that came into MD/VA ca 1785-1790 back in Donegal several generations back. I was there for a second time in Sept. of 2011 and met a genealogist there I commissioned to reseach my mother's roots and seek a link to the two afore mentioned lines in America in pre-1800 history.
William married Ruth Towson in MD, the rest married in Rockbridge/Botetourt area between 1796-1802 and all but Nancy Dougherty Leece moved into SW-VA. She and Jacob Leece remained in Lexington until his death, then she moved to Russell County to live with her son, Samuel Leece.
I have quite an extensive list of the Michael Mor line, but that line is well documented on many web postings and family trees.
Please contact me direct at WB4RJE@arrl.net
since the Roots Web message links do not work well for me at times..Robert