Elphinstone’s parents, though owning great estates in Stirlingshire, Dunbartonshire and Lanarkshire, were harassed by debt and could make little provision for their numerous children. ‘To acquire his education and business together and without expense’, Elphinstone entered the navy as an able seaman,
While on leave in October 1774 he unsuccessfully contested Dunbartonshire, with the support of Sir Lawrence Dundas, against Sir Archibald Edmonstone. Before his petition was heard he was sent to sea, and despite the efforts of his agent and friends the House, on a division, refused an extension of the time limit for receiving it. After serving on convoy duty and in American waters, he was sent by Howe in 1778 to defend East Florida, and distinguished himself in the operations leading to the capture of Charleston in May 1780, after which his ship was ordered home.
During his absence his brother William, Sir Lawrence Dundas, and the Marquess of Graham had concerted plans to support his candidature for Dunbartonshire against the Argyll interest.
Arriving in November 1782, he joined his brother-in-law William Adam in opposition to Shelburne and voted against the peace preliminaries, 18 Feb. 1783. He became a favourite of the Prince of Wales, who in June appointed him to succeed Sir John Gordon as his Scottish secretary. In December 1783 he followed his friends into opposition, but was a member of the St. Alban’s Tavern group favouring a union of parties. Henry Dundas believed that at the general election in 1784 Elphinstone would ‘certainly be turned out and a friend brought in’,
His only recorded speech in this Parliament was on 11 June 1788 when, during the trial of Warren Hastings, he protested against the closing of certain passages giving access to Westminster Hall.
He died 10 Mar. 1823.
