Stephenson was established in London at least as early as 1749, and in 1753 was a ‘very considerable Spanish and Portugal merchant’.
In March 1764, when Grenville’s Administration was supporting Clive in his contest with Sulivan at East India House, Stephenson was mentioned as a possible director, and in 1765 was elected as a Sandwich candidate.
In March 1774, on the death of Robert Jones, another follower of Sandwich, Stephenson succeeded to his contract for victualling troops in Nova Scotia and Newfoundland, and during the American war obtained further contracts in Newfoundland, Nova Scotia, and West Florida.
Only two speeches by Stephenson are reported during nearly 30 years in Parliament; in a debate on hops, 18 Apr. 1774, and to move that an order for calling over the House be discharged, 6 Feb. 1782.
He died 17 Apr. 1794, in his 85th year.
