Jackson entered the navy office as a clerk about 1743. In 1766 on Chatham’s recommendation he was transferred to the Admiralty by Sir Charles Saunders, and in 1769 became judge advocate and second secretary to the Board. After the fall of North’s Administration he retained his post as judge advocate, but was dismissed from his secretaryship with a pension of £400 a year. ‘The strange conduct of the Admiralty’ in dismissing ‘probably the most useful man at the Board’ was raised in the House of Commons, 12 May 1783, by John Buller senior, who declared that ‘a more able and honest man never served the public’.
Before the general election of 1784 Jackson appears in Robinson’s lists of those to be brought in, and willing to pay ‘£1,500, or perhaps somewhat more’.
Jackson was keenly interested in improving inland waterways, and according to the Gentleman’s Magazine (1822, ii. 644) ‘employed his leisure hours in making the river Stort navigable’. He died 15 Dec. 1822.
