For some years before the Union, elections for this wild and unproductive county had been largely dominated by Alexander Montgomery, a radical squire who relied more upon his general popularity than on his tenantry and who had materially assisted in the return of Henry Vaughan Brooke. The Marquess of Abercorn challenged them in 1797, but did not then succeed. Montgomery’s death in September 1800 and the increased importance of the county seats caused by the disfranchisement of all the Donegal boroughs at the Union prompted Abercorn to step forward again and to assist in the return of his brother-in-law, Lord Sudley, at the subsequent by-election. He was assured of government support. Abercorn was a politician of some weight in Ireland and, apart from considerable property and interest elswhere, drew some £9,000 p.a. from Donegal. His only other competitor for the county representation proved to be the Marquess of Conyngham, who likewise combined substantial interest elsewhere in Ireland with three estates in Donegal, one of which comprised 30,000 acres of mountainside. The two magnates failed to come to terms with each other.
At the general election of 1802 Abercorn increased his stake in the county by supporting Stewart as Sudley’s colleague and forcing Brooke to stand down. In 1806, however, his personal interest was decimated by the death of his agent James Hamilton, for whose life many of his own tenants held their freeholds: freeholders suddenly became tenants at will and were immediately disfranchised. The result was that Conyngham put forward Brooke, whom Sir James Stewart refused to oppose; and Abercorn’s heir Lord Hamilton (not yet of age) retired. Abercorn’s new ally James Sinclair of Holy Hill offered to stand instead, but found his prospects hopeless.
The good cheer that flowed in Donegal did not reach Abercorn and Conyngham, who continued to feel that the issue between them remained undecided. Thus late in 1807 when it was rumoured that Stewart’s death, and therefore a by-election, were imminent, the Castle brought the vexed question of Donegal politics and patronage under review. Wellesley admitted the supremacy of Conyngham’s electoral interest but was inclined to defer to Abercorn’s superior political weight. Castlereagh thought along similar lines, but advised the Castle to settle the matter of patronage speedily. As it happened it was Brooke and not Stewart who died, although this did not prevent a clash between the two interests at the subsequent by-election. Montgomery, who claimed a substantial interest of his own, stood supported by Conyngham and, ‘in opposition to the wishes of their landlords’, by the tenantry of Lord Sudley, Conolly and Pakenham. He was opposed by Gen. Hart, supported by Abercorn and, reluctantly, by Mountjoy and (in rather secretive fashion) by the Castle. The candidates spent £9,000 each. Once again Conyngham succeeded, much to the chagrin of Wellesley, who felt that the Castle had done enough for Abercorn and Hart. The latter petitioned unsuccessfully against his defeat on the ground (among others) that his opponent had induced Catholics to personate Protestants in order to avoid certain registration requirements.
This was the last dispute between the two families in this period. By 1812 Abercorn’s personal interest had been restored to its former healthy state and a new Marquess of Conyngham was obliged to compromise. In fact they joined forces to return candidates favoured by the government. Conyngham decided against supporting Montgomery, which meant that the latter retired. The Castle suggested Hart as Stewart’s colleague and, after some wavering, Conyngham agreed, telling Hart that he did so to meet the wishes of the gentlemen of the county and to avert a contest.
The spirit of this compromise was maintained at the next election, after much manoeuvring. It was now Conyngham’s aim to return his heir Lord Mount Charles; to counter this, Abercorn encouraged the pretensions of Lord Clonmore, the Earl of Wicklow’s heir, married in February 1816 to his daughter. In doing so, he did not wish for a confrontation but an exchange of new Members for old: if Hart made way for Clonmore soon, unopposed by Conyngham, he would not oppose Mount Charles subsequently. The sitting Members, when they got wind of this development, were thrown into confusion. Hart, who could not envisage a junction with Conyngham, at first declared his willingness to resign in Clonmore’s favour, which would have suited Abercorn’s design by enabling Clonmore and Mount Charles to unite at the general election. On finding that there was to be an accommodation with Conyngham, however, Hart refused to resign, 12 Jan. 1817, and made overtures to his colleague to resist the newcomers. Sir James Stewart could not altogether refuse him, though he had no intention of facing a contest and hoped to come in with Clonmore rather than with Hart. Abercorn was disgruntled at Hart’s conduct, but thought he must honourably stand by Hart if he persisted. Even so, he did not envisage any junction of Hart and Clonmore against Conyngham; and believed that Hart must first cede to Clonmore. In the event, Clonmore ceded to Hart and Sir James Stewart made way for Conyngham’s heir.
Number of voters: about 6000 in 1815