Not sure if you know but Thomas Dugan/Dougan lived in St. Christopher (St. Kitts), West Indies before he and his family immigrated to the Colonies. It was there that his sister Catherine died in 1728. From Julian Kelly's Book, Johnston-Dugan The Related Families Near Enoree River, South Carolina, in the Late 1700's and Their Origins and Dispersion, page 18, "The inscription by Thomas Dougan could be transcribed into modern punctuation as follows: "Thomas Dougan's Bible, which [was] his sister's, Catherine Dougan's, who departed this life on the Island of St. Christopher in the [year] A. D. 1728." On page 19 he writes,"St. Christopher was discovered by Christopher Columbus in 1493, and in 1623 became the first English settlement in the West Indies." and " It seems unlikely that a young girl or unmarried woman would have migrated to settle in St. Christopher alone, or even with her brother, unaccompanied by her parents. Therefore, it appear reasonable to conclude that the family of Thomas Dougan and his sister Catherine were settlers of the Caribbean British colony of St. Christopher at some time prior to Catherine's death, and possibly as much as a century earlier. Also, it seems unlikely that Thomas would have received Catherine's Bible on her death, had he not been in St. Christopher when she died there in 1728." "It seems probable that, as other Scots were settling the "Plantations" of the north of Ireland, the Dougan family chose to settle that of St. Christopher. However, when many emigrants of Scottish extraction were pouring into Pennsylvania from Ulster, the Dougans must have come to join those of similar background, moving to Pennsylvania and choosing their brethren of the Paxtang area as neighbors." "Epitaphs in the Paxtang Presbyterian Church cemetery show that Susannah Collier died 9 Sept. 1781, aged 74, and that her husband, James Collier, died 31 Mar. 1788, aged 85. Therefore, James Collier was born in 1702-3 and Susannah Dougan in 1706-7; they married in 1731, he at about age 28 and she at about 24. Therefore, the Dougan family and James Collier were presumably in the same area of Pennsylvania at the time this marriage took place. Therefore, it appears that Thomas Dougan and his children came to Pennsylvania between 1728 and 1731. From the known or implied dates of the marriages of Thomas Dougan's known children, they all appear to have been born prior to the family's arrival in Pennsylvania, and therefore presumably in St. Christopher. The recorded birth date of Margaret, daughter of John Johnston, shows that Mary Dougan married John Johnston by 1740. Known or calulated birth dates of their children suggest that Thomas Dougan, Jr. proably married abt. 1745, and that Robert Dougan married widow Margaret Park by 1747. These projected marriage dates and the naming pattern discussed previously (Scottish Naming Pattern)would suggest that these three all may have been younger than Susannah Dougan Collier, and therefore born aft. 1707. This futher suggests that they were children or very young adults when the Dougan family came to Pennsylvania. Therefore, they came with their parents, or at least their father, rather than independently."