I just happen to have a few notes with me on this family; I am sure I have more at home:
Arhur Nelson, (notes from his will)7 Dec 1785 - my daughter Sarah Luckett, daughter Jane Nelson, land called Nelsons Island, 223 acres; to son John land called Huckleberry Hill, 38 acres; land called No More, 33 acres; land called Point of Rocks, 30 acres. (This is on the Potomac River, southwest of Frederick.); land Hooks Neglect, land Hobson's Choice, including his dwelling plantation, 124 acres; Carrolton, 66 acres. (more here which I did not copy).Arthur's wife was Lucy Nelson, grandson was William arthur Nelson Luckett, son of Sarah.
In the will of Elizabeth Nelson Delashmutt, she mentions son Basil, son Linsey, daughters Elizabeth Botler and Rachel Semaster; grandson Philip Nelson Noland; dtr. Anne Warfield; son Elias. (she gave Philip slaves) Grandchildren Elias Delashmutt, and his sister Elizabeth Delashmutt, issue of her son Elias.25 May 1785, witnesses Arthur Nelson, Ralph Briscoe, Roger Nelson.Probated January 1786.(Ralph Briscoe was the husband of Sarah Delashmutt)
Will of Elias Delashmutt, April 1778.Grandson Peter Delashmutt, land Childrens Chance, Feestones (?) Road where son Elias lives; grandson William Delashmutt, grandson Philip Nelson Noland; grandson Elizs Delashmutt, son-in-law Edward Botler, daughter Rachel Semaster, land Moreland.Mentions son Basil, land Ramble and Swedes Folly; daughter ann, daughter Elizabeth Botler, grandson Elias Botler, son Lindsay's wife Elizabeth.
You could write the courthouse in Frederick for copies of this will, which you should do because I probably made some errors, and left things out.The Frederick County Historical Society, Church Street, Frederick might have books for sale with information on this family.Millard Millburn Rice wrote several books on that area of Frederick County.I am sure the Delashmutts lived at one time in what is now Jefferson (Trappe), which is halfway between Frederick and the Potomac River near Rt. 340.