Findagrave.com has a bio written by Mark Hale which reads: Anthony was the eighth and last child of Francis and Alice (Savage) Thornton, born presumably on his father's plantation in "Old" Rappahannock Co., Virginia. [Biographies of his parents linked to this one contain erroneous information.] His birth coincided with the approximate time of his mother's death and when his father remarried to widow Jane Harvey, Anthony would have gone with his father to live at the Harvey inheritance in extreme eastern Stafford (now King George) County.
As early as 1706, when Anthony was about age fifteen, he was granted by a deed of gift from his father and stepmother 684 acres in Stafford and Westmoreland counties. Following the death of Jane Harvey Thornton, Francis Thornton 1st left the Harvey inheritance and returned to the Rappahannock River, but it seems more likely that Anthony remained on his plantation in Stafford and Westmoreland, which would have been closer to the vicinity of the Peter Presley plantation Northumberland House. His marriage to Presley's daughter Winifred probably occurred there in Northumberland County.
Anthony acquired considerable real estate, including an acreage in Essex (later Caroline) County that was inherited by son Anthony 2nd. The senior Anthony and/or his son Presley probably managed the property of Peter Presley in Northumberland County in Presley's old age. Peter Presley, the "last of his name" and advanced in years, was murdered in 1750 by two of "his own servants" who were executed for the crime. Anthony Thornton's will was proved 1757 in Stafford County.

William and Mary College Quarterly Historical Magazine, Volume 4, Page 93 reads: Anthony Thornton, of St. Paul’s Parish, Stafford county born --- 27, 1695, died 1757. He was a justice of Stafford, and, having been for a time out of the commission, was restored in 1733. He married Winifred, daughter and heiress of Col. Peter Presley of “Northumberland House,” Northumberland county. His will dated January 3d, and proved November 8, 1757, in Stafford county. . . .

According to “U.S. and International Marriage Records, 1560-1900”, Anthony Thornton married Winifred Presley in 1720 in Virginia. Another source says they were married in Northumberland County in 1721. I’ve found no proof for either date. Winifred was born in 1695 the daughter of Capt. Peter Presley and died after 1757 probably in Stafford County, Virginia

He is listed on the Quit Rent Roll of 1723 (taken from the Register of Overwharton Parish – Stafford County) as owning 350 acres for which he paid £ 0.7.0

Virginia County Records SPOTSYLVANIA COUNTY 1721-1800 DEEDS DEED BOOK A 1722-1729 page 91 Decr. 25, 1723. Francis Thornton of Essex Co. and Anthony Thornton of Stafford Co., Gentl., to James Sparks, planter. 200 a. of land in Spts. Co., 530 lbs. of tobacco yearly for 99 years. Witnesses: Henry Martin, Law. Battaille. Rec. April 7, 1724.

Virginia County Records SPOTSYLVANIA COUNTY 1721-1800 DEEDS DEED BOOK A 1722-1729 page 91 Decr. 25, 1723. Francis Thornton of Essex Co. and Antho. Thornton of Stafford Co., Gentl., to Leonard Night, planter. 140 a. of land in Spts. Co., 530 lbs of tobacco yearly for 99 years. Witnesses: Thos. Smith, John Mulkey. Rec. April 7, 1724.

Virginia County Records SPOTSYLVANIA COUNTY 1721-1800 DEEDS DEED BOOK C 1734-1742 page 140 Nov. 4, 1735. Anthony Thornton of Stafford Co., Gent., to Sharshall Grasty of King and Queen Co. 270 a. (part of pat. granted Anthony and Francis Thornton, April 19, 1720), now in St. Geo. Par., Spts. Co. Wm. Waller, G. Home, Antho. Strother, Edwd. Herndon, Junr. Nov. 4, 1735. Winifred, wife of Anthony Thornton, acknowledged her dower, etc.

Virginia County Records SPOTSYLVANIA COUNTY 1721-1800 DEEDS DEED BOOK C 1734-1742 page 141 April 6, 1736. Vincent Tapp of St. Geo. Par., Spts. Co., to John Ellson, of Par. and Co. afsd. 175 a. in Spts. Co., part of a tract granted Francis and Anthony Thornton, by pat. April 19, 1720; 450 a. being sold to Elizabeth Tapp, as by Deeds from Francis Thornton and Mary, his wife, and Anthony Thornton and Winifred, his wife, Sept. 4, 1722, 175 a. of the 450 a. being conveyed by sd. Elizabeth Tapp, as by Deed of Gift, Nov. 3, 1724, to sd. Vincent, etc., etc. Witnesses, Jno. Curtis, Henry Sparkes. April 6, 1736.

Known children born to this union:
1. Presley Thornton born about 1721 in Virginia, died 1769, married Elizabeth _____
2. Francis Thornton born July 20, 1725, died in Aug 3 1784 and married Sarah Fitzhugh
3. Anthony Thornton born November 15, 1727 in St. Paul's Parish, Stafford Co., Virginia
4. Winifred Thornton born Sept 23., 1729, died Sept. 29, 1965, married William Bernard who was a lawyer in Westmoreland County. President Monroe studied law in his office.
5. Judith born October 3 (or November 13), 1731, died June 19, 175, 7 married Thomas Buckner
6. Peter Thornton born March 29, 1734, death unknown, married Ellen Bankhead

Historic Virginia Homes and Churches by Robert Lancester reads:
Oremsby, an estate not far from Guiney’s Depot on the Richmond, Fredericksburg and Potomac Railraoad, was one the property of Anthony Thornton, of Stafford County, who married Winifred, daughter of Colonel Peter Presley, of Northumberland House, Northumberland County, and died in 1757. The Ormesby homestead is one of those interesting-looking, rambling frame houses which in old Virginia fashon grew with the needs of the family that lived in it. It is said that Anthony Thornton I built the oldest part of the hosue in 1715 and gave the plantation to his younger son, Anthony II, who was in turn succeeded by this son Colonel Anthony Thornton III, who as county lieutenant of Caroline commanded the militia of that county at the siege of Yorktown. Later Colonel Thornton sold Ormesby to his brother Thomas Griffin Thornton and removed to Kentucky.
Thomas Griffin Thornton was in this day one of the most famous fox-hunters in Virginia, and the old sporting magazines contain anecdotes illustrative of the great excellence of his hounds. He finally sold Ormesby to his brother John, whose heirs still own it. Before removing to Ormesby, John Thornton had owned and lived in Fairfield near Guiney’s. It was in an outbuilding known as “the office” at Fairfield that Stonewall Jackson died.

Anthony’s will was dated January 3, 1757 and probated the same year on November 8th. The will reads as follows:
Stafford County, Virginia Will Book page 331
In Name of God Amen I Anthony Thornton of Stafford County being in perfect sence do make this my last will & testament.
Imprimis I give to my son Presly Thornton the several negroes he has in his possession to which I have a Title in right of my wife with their several increased except Negro Grace and her children which I have before given and do now confirm to my son Francis and his heirs forever.
Item I give to my beloved wife Winnefred the tract of land whereon I now live during her natural life, & after her deceased to my son Francis & his heirs.
Item I give to my son Anthony Thornton all the Land I have at the Mountains to him and heirs.
Item I give to my daughter Winnefred Bernard a tract of land on Nash run in Spotsylvania County contianing 650 acres to her & her heirs of her body.
Item I give to my son Peter Thornton a tract of land on Mattopony containing 1313 acres to him and heirs forever with all the negroes, stock of cattle, hogs, horses and all other things on the said plantation I also give to my son Peter ten head of young cattle from the Plantation I now live on together with Negroes Jacob, Rachael , Roger & Violet to him and heirs.
Item I give to my wife Winnefred a Tract of low ground where on William Conner now lives during her life and after her death to my son Anthony and heirs.
Item I give to my said wife negroes James, Sarah, a boy Billy & little Jenny durig her life and after her death to my son Peter & heirs
Item I give the rest of my negroes not before disposed to my said wife to be at her disposal, together with my stocks of horses cattle hogs & sheep.
Item I give the rest of my estate to be equally divided between my wife and my son Peter Thornton. My desire is that my estate shall not be appraised.
Lastly I appoint my son Peter Thornton Executor of this my last will & Testament...3 January 1757                Anthony Thornton
Jacob Johnston
Martha Whiting,
Maxfield Whiting

At Court held for Stafford County 8th November 1757. Last will produced in court....proved......certificate granted for obtaining probate.......


References:
DAR and SAR Applications
U.S. and International Marriage Records, 1560-1900
Findagrave
Spotsylvania County 1721-1800 Deed Book C 1734-1742
The Buckners of Virginia and the Allied Families of Strother & Ashby – Bayne
The Statutes at Large – Hening
Historic Virginia Homes and Churches
Register of Overwharton Parish – Stafford County
Spotsylvania County, VA Records