Thomas had arrived in the Colony of Virginia by 1677. During the next three years he seems to have traveled several times between England and the Colonies. It was during one such journey, in 1679, that he was taken prisoner by Algerian pirates and was ransomed by the villagers of Glooston, the parish in Leicestershire, England where his father was then serving as rector. This event was recorded in the Register of Glooston Parish which states "July 28, 1679: To redeem Thomas, son of Mr. Owsley, Rector of Glooston, taken by the 'Algerines,' the sum of 1.11.3 was collected."
By 1680, at the age of only 22 years, he held the position of Clerk of the Stafford County Court, a position he held when he died in 1700. In 1681/82, he was authorized to traffic in a variety of commodities with the Nantecoke Indians of Maryland. In the next twenty years, Thomas would also serve as Justice of the Peace, a captain of the Potomac Rangers (1692), a major in the county militia (1698/99), Sheriff of Stafford County (1696) and was twice elected to the Virginia House of Burgesses (1692-1696 and 1698).
Thomas's land patents, totaling over 2000 acres, were in the Northern Neck of Virginia, including some on the shore of the Potomac River.
Major Thomas Owsley died 10 October 1700 in Stafford County and was buried there on his plantation, now located on the Fort Belvoir Military Reservation, in what is now Fairfax County. The exact date of his death is known from a 1748 survey map on which is noted his grave and the comment "Owsly buryd there, as by a tomb stone, he dyed October ye 10th 1700."
About 1680, Thomas married Ann Harris, apparently the only child of Lieutenant William Harris, a former British Army officer who was in Stafford County in the 1660s, and whose will of 1698 left all of his land to his Owsley grandchildren. About 1703, Ann was married to John West, by whom she had two sons (Hugh, John), and after his death, married for the third time in 1718 to John Wheeler. From the death of Thomas Owsley in 1700 until 1739, Ann Owsley West Wheeler is often mentioned in land records, indicating that Ann survived Thomas by many years.
Thomas Owsley left six children: Jane, who married James Gregg and had four sons (Thomas, James, Matthew, John) and four daughters (Lucy, Sarah, Lettice, Jemima); Ann, who married Isaac Kent and had at least one son (Isaac); Mary, of whom nothing is known; Thomas, who married 1) Ann, by whom he had one son (Thomas), and 2) Ann Hudson, by whom he had six sons (Thomas, John, William, Newdigate, Poyntz, Weldon) and four daughters (Sarah, Ann, Elizabeth, Jane); Poyntz, of whom nothing further is known; and Sarah, of whom nothing further is known.
First Mississippi Company Member: Susan Clark Slaymaker