I have another book with me today: "Pioneers of Old Monocacy, the Early Settlement of Frederick County, Maryland, 1721-1743" by grace Tracey & John Dern:
Page 226 - "The sprigg family was descended from Thomas Sprigg who arrived in this country from England about 1655.He was a Sheriff in Calvert County and died there in 1704.His children included Ann (wife of Philip gittings), Martha (wife of Thomas Prather), Saah (wife of John Pearce), Eleqanor (wife first of Thomas Hilleary and then of John Nuthall), Elizabeth (wife of Robert Wade), Mary (wife of Thomas Stockett) and Thomas Sprigg, Jr., who married Margaret Mariarte.(There is further information about Thomas Jr.)
Page 89 - "Thomas Hilleary was Jones' nearest neighbor, although he didn't have his tract 'Sugar Loaf' surveyed until April 7, 1741.It was located 'on a ridge a small distance from a spring that runs into bennett Creek below the main fork of said creek,' in the area east of today's Park Mills. (This in the lower part of the county near where the Monocacy River empties into the Potomac River. The foothills of Sugar Loaf mountain are in Montgomery County and most of us consider it 'our' mountain.)
"Earlier, on February 22, 1740, Thomas Hilleary had 27 acres surveyed 'on the Potomac near the corner of Arthur Nelson's land.'This he called 'Arrow Point.'On the same day 58 more acres were surveyed for him, also on the west side of the Monocacy river, situated in the large bend of that river between present-day Greenfield and Furnace Ford.This parcel he called 'Pick Axe.'In 1762 William Hilleary, presumable a brother of Thomas enlarged the 'Sugar Loaf' parcel with a resurvey.Thomas Hilleary is believed to have been the third of that name.His grandfathr had come to Maryland from England in 1639.His father, the second Thomas Hilleary, had received a patent for 'Three Sisters' located near present-day Hyattsville in Montgomery County.(I believe this should be Prince George's County; we have a Hyattstown in Montgomery County).He had married Eleanor Young, but died in early 1729 leaving his widow with six children.Six Hilleary households were listed in Frederick County in the 1790 census; three in 1800.The latter census, coupled with Varle's map of 1808, suggests that some of this family had moved on to the Petersville District of southwestern Frederick County before the end of the 1700s.(This is in the Brunswick area.)
The authors have listed references for all this information.