Downing Street was created by Sir George Downing in 1682-83, although the only houses to remain of the original cul-de-sac are numbers 10 and 11, famously remodelled by Sir Robert Walpole in 1732-35 at the expense of the Treasury. In the 1760s number 15 was in the possession of John Sargent, and in 1764-65 Robert and James Adam were commissioned to design various rooms for the house, including the drawing room, dining room, a dressing room, a bedroom, and the staircase, although none of these were executed.

It is possible that the John Sargent in question was John Sargent (1714/15-91), a merchant and politician, working extensively in the cloth trade, first with his uncle, then with the navy, and finally in a private capacity with an extensive import business from Africa and India. From 1755 he diversified into the profitable shipping of mail between Falmouth and the Caribbean, and an enslaved people trans-shipment factory in Sierra Leone. He was also a director of the Bank of England in 1753-67, and an MP for Midhurst, Sussex, in 1754-61, and for West Looe, Cornwall, in 1765-68. He was respected as an expert on the subject of colonial trade, but disliked the work, and voluntarily removed himself from public office in 1768. Interestingly, Sargent's years in politics and banking - and a friendship with Thomas Walpole - coincided with Adam's commission in Downing Street, and it is probable that this John Sargent was Adam's patron. Sargent spent his later years making land speculations in America, although this was cut short by the American War of Independence, and from that time he decided to entrust his business affairs to his younger partners. It is not known why Adam's designs for 15 Downing Street remained unexecuted.

Literature:
A.T. Bolton, The architecture of Robert and James Adam, 1922, Volume II, Index pp. 37, 86; D. King, The complete works of Robert & James Adam & unbuilt Adam, 2001, Volume II, pp. 167, 180; S. Bradley, and N. Pevsner, The buildings of England: London 6: Westminster, 2003, p. 262; J.B. Lawson, 'Sargent, John (1715-91) of May Place, Crayford, Kent', History of Parliament online; D. Hackcock, 'Sargent, John', in Oxford Dictionary of National Biography online

Frances Sands, 2012