1715 William Williamson of Accomack CO, VA got "Horse Island", 107 acres located in Angola Neck, west side of Rehoboth Bay, DE. I believe at that time Angola Neck would have been part of Dorchester, MD. In 1717 William Wiliamson of Accomack, VA received "Benifield" 500 acres in Angola Neck. 1720, William Williamson, of Dorchester, MD given power of attorney (8OLD22). This is first record that shows he actually ended up in Maryland. 1732, William Williamson of Dorchester Co, MD land transaction for 107 acres, in Angola Neck, apparently Horse Island listed above. 1728 William Williamson, Dorchester Co, MD, binds himself as clerk to Charles Goldsborough for 3 years (8OLD238). 1735 will for William Williamson filed in Annapolis left 300 acres in Sussex, DE (apparenty some of the land from above) to sister, Rachel Huston of Somerset County, MD. Your record mentions Williamson's daughter Sarah Houston. Apparently mother died before administration was complete. So any way we know that William Williamson started in Accomack. So how did he get there?
Short history of Williamson's on Delmarva Penisula. William Williamson and wife arrive Kent Island winter 1637/38 with Evenlin. He went across the Chesapeake to hell Evenlin build mill, not sure if he stayed there or not. He was not on tax list for Kent Island in 1642. Many of original inhabitants of Kent Island came from Accomack, VA. After Clairborne lost Kent Island to Maryland many of inhabitants fled, some back to Accomack. In 1653 Claiborne got 500 acres at Pamunkey on north side of York River for transporting 100 people to Virgina, two of which were William Williamson and wife Ann. Not sure where in Virginia they were transported to, but could have been back to Accomack. In 1663 William Williamson got 200 acres in Rappahannack Co, VA for transporting 4 people to VA. (same William? who knows). Next Williamson. In 1665/6 David Williamson got at least 6000 acres of land in Accomack for transporting people. 1666 Lt Col Henry Meese got 2000 acres south side of Potomac for importing people to Va, one of which was William Williamson. 1668 Thomas Harmon granted lane originally granted to William Williamson. 1668,1671, 1674, 1690, 1698, 1701 various men got land for transporting in William Williamson (he may have gone back and forth to England, hard to believe that there were that many William Williamson's in Accomack/Northampton. Land received in the 1698 case involved Horse Island in Rehoboth Bay, DE. William Williamson not on tax lists for Accomack CO 1663-1695). David Williamson is shown 1664,66,67,68,69, and 71. But there are other records. Will of John Parker, Sr (written 1692,filed 1695)left part of his estate to William Williamson (Accomack). 1701 Samuel Fittiman left something in his will to Wm Wiliamson (Accomack). Will of Sebastian Silverthorne 1712/1714 named William Williamson tutor to son John and executor of estate. 1704 William Williamson on Accomack CO Rent Rolls (he apparently never owned land in Accomack, never on tax lists, only rent rolls). So this gets us to 1715 when William Williamson of Accomack, VA got land in Delaware.