When Cockburn unexpectedly succeeded to the baronetcy, the estates of the bankrupt Langton branch of the family had long been in the possession of their principal creditors, the Cockburns of Cockburn, who also claimed the hereditary office of principal usher. In 1755 James, after long litigation, failed to establish his right to the honour, which with all other Langton property was auctioned in 1757 and passed out of the ownership of both branches of the family.
As a youth Cockburn entered business in London with Henry Douglas, a wealthy Scots-West Indian merchant, whose daughter (with a dowry of £10,000) he married. In May 1760 he was appointed a commissary under Prince Ferdinand,
After the war he was closely associated with Colebrooke in East India Company affairs; included in the House list of candidates for the court of directors in 1765, he was dropped at the insistence of Lawrence Dundas and Lord Holland,
Cockburn was now a rich man and ambitious of restoring his family’s prestige in Scotland. By 1766 he had bought back the office of heritable usher and in 1769 a portion of the Cockburn estates.
Cockburn joined the East India group of M.P.s led by Laurence Sulivan and on 30 March seconded his motion for a bill (subsequently dropped) ‘for the better regulation of the East India Company’.
Little affected by the financial crash of 1772, Cockburn lavished money on his burghs to counter the interest of Sir Lawrence Dundas.
It would not be suitable for him nor his situation in life to be the ostensible man in fighting the Burghs and afterwards retire, making his bow to them and desiring them to choose Sir Adam Fergusson or any other person whatever.
After numerous conferences, the Hamilton guardians pronounced their ultimatum: unless Cockburn accepted ‘second place’ the Hamilton interest would be given to another candidate. At a meeting on 23 Aug. at Colebrooke’s house, attended by Stuart, Charles Fergusson (Sir Adam’s brother), and John Fordyce, the Scottish receiver general, Cockburn swallowed his pride and agreed to the terms.
Cockburn uniformly supported Government in Parliament. In 1776 he and his partner Henry Douglas secured a valuable contract for supplying 100,000 gallons of Grenada rum to the troops in America;
North wrote to the King soon after his resignation:
Sir James Cockburn is in the extremest distress. He has received the pension in the name of Lady Cockburn. His Majesty will consider whether it will be right to suppress this pension altogether or to leave Lady Cockburn in this, or to insert her in some other list, on account of her distress and the former connexions of her father with his Majesty and the Royal Family.
The King replied:
In 1784 he had little chance of re-election; and, without money or influence, he was discarded by the combined Hamilton, Buccleuch and Queensberry interests.
In 1786 Cockburn, in desperate financial straits, sought refuge from his creditors by obtaining diplomatic immunity as secretary to the Prussian minister, an abuse of privilege against which Lord Carmarthen protested to the King.
He died 26 July 1804.
