The principal interest belonged to the Stewarts earls of Galloway; they controlled Wigtown and Whithorn, and when either town was the presiding burgh could secure the return of their candidate. Stranraer was controlled by the Dalrymples, earls of Stair; and the Gordons of Kenmure had considerable influence in New Galloway.

In 1754 the Duke of Argyll intervened in this constituency on behalf of James Abercrombie, and to counter him Lord Galloway made an alliance with John Hamilton (formerly Dalrymple) of Bargany: Hamilton was returned for the Burghs, and the Dalrymple interest in Wigtownshire was given to James Stewart, Lord Galloway’s brother.1 In 1761, when Wigtown was the presiding burgh, Galloway put up Archibald Montgomerie, who was also a candidate for Ayrshire, to hold the seat for his son Keith Stewart, who was away at sea. The Dalrymple interest, backed by Argyll, sponsored the candidature of Hutchison Mure, uncle of William Mure of Caldwell. Stranraer and New Galloway voted for Mure; Wigtown and Whithorn for Montgomerie, who was returned on Wigtown’s casting vote. When Montgomerie chose to sit for Ayrshire, Keith Stewart came in for the Burghs; only to vacate his seat two months later to John Hamilton, as part of the compromise over Wigtownshire.2

At the general election of 1768, when Whithorn was the returning burgh, the Galloway interest again had the constituency at their disposal. George Augustus Selwyn agreed to return Lord Garlies at Ludgershall, and was himself returned for Wigtown Burghs as an insurance against his defeat at Gloucester. When Selwyn was successful at Gloucester, Chauncy Townsend, a nominee of the Treasury, was returned in his place; and on Townsend’s death, William Stewart of Castle Stewart of a junior branch of the Galloway family.3

In 1774, with New Galloway the returning burgh, the Dalrymples expected to win the constituency by an alliance with John Gordon of Kenmure. In the hope of getting a seat in England for his son Lord Dalrymple, Lord Stair, on the recommendation of Sir Lawrence Dundas, chose as his candidate William Norton; and the Galloway candidate, Henry Watkin Dashwood, the 7th Earl’s brother-in-law, was also an Englishman. (This was the only occasion during this period when a Scottish constituency was contested solely by Englishmen.) Norton was returned, as was expected, but unseated on petition.4

Lord Stair was a pro-American and an admirer of Chatham, but in 1780, with the constituency again at his disposal, he offered it to Administration in exchange for a diplomatic appointment for Lord Dalrymple. Lord North named William Adam.5 In 1784 the Dalrymples were again in the ascendant, having won control of Galloway’s burgh of Whithorn; and William Dalrymple was returned against George Johnstone, the Galloway candidate.