Barton, Thomas (1695–1780), wine merchant and property owner, was born at Curraghmore, Co. Fermanagh, on 21 December 1695, the eldest son of William Barton and his wife, Elizabeth, daughter of John Dickson of Ballyshannon, Co. Donegal. After being ‘bred up a merchant’ by his uncles, Thomas and William Dickson, at Ballyshannon, near his home, he moved to France to become a factor at Marseilles and Montpellier before setting up a business at Bordeaux (1725). At first he traded French brandy for Irish wool; later claret was the chief item of his trade. On 1 November 1722, before setting off for France, he married a cousin, Margaret Delap (d. 1775) of Ballyshannon; they had an only son, William Barton (1723–92) wine merchant and property owner, born at the Delap house (1 November 1723), whom Thomas later made his partner (1743).
By 1747 Thomas Barton was sufficiently prosperous to be able to purchase a small vineyard, Le Bosq, near Saint-Corbian in the Médoc. He inherited a small estate at Curraghmore from his father and for £30,500 purchased (1752) an estate near Fethard, Co. Tipperary, adding to it the adjacent house and demesne of Grove comprising 292 plantation acres (1757). Grove was to remain in the Barton family until 1955. When William Barton married Grace Massy, a daughter of George Massy, dean of Limerick, acquiring a dowry of £3,000 (1754–5), Grove and the property around Fethard were settled on him for life. It appears that the property included the town and lands of Fethard, worth (1765) more than £1,600 p.a., and that it contained (1775) c.2,650 Irish acres, bringing an estimated rent of £1,500 p.a. By 1765 a rift had occurred between father and son. William, who seems to have been more concerned with Irish than with French interests, fought a duel with a Cornelius O'Callaghan (1742–97), MP for Fethard (1768–85), over a contest to elect a sovereign of Fethard (1772), which would have advanced his interests in the borough.
Thomas Barton (‘French Tom’) died at Bordeaux on 18 October 1780. The business in France passed then, if not before, to William. Thomas left large sums to William's six sons. To the eldest of these, Thomas (1757–1820), he left his Irish property, which caused a quarrel between William and Thomas and litigation that ceased only with William's death in 1792. Thomas the younger was owner of Fethard, MP for the borough (1783–97), and a whig. William Barton's fourth son was Hugh Barton (qv), who eventually took over the wine business started by his grandfather.