John married Margaret Georgiana Poyntz on 20 Dec 1755 in Althorp Manor, Brington, Northamptonshire, England. Margaret (daughter of Stephen Poyntz, PC and Anna Maria Mordaunt) was born on 27 Apr 1737 in Midgham, Berkshire, England; died on 18 Mar 1814 in St. Albans, Hertfordshire, England; was buried on 30 Mar 1814 in St. Mary's, Gt. Brington, Northamptonshire, England. [Group Sheet]

1. Lady Georgiana Spencer, Duchess of Devonshire was born on 7 Jun 1757 in Althorp Manor, Brington, Northamptonshire, England; died on 30 Mar 1806 in Devonshire House, Piccadilly, Middlesex, England; was buried on 9 Apr 1806 in Derby Cathedral, Derbyshire, England.
2. George John Spencer, 2nd. Earl Spencer was born on 1 Sep 1758 in Wimbledon, Surrey, England; was christened on 16 Oct 1758 in Wimbledon, Surrey, England; died on 10 Nov 1834 in Althorp Manor, Brington, Northamptonshire, England; was buried on 19 Nov 1834 in St. Mary's, Gt. Brington, Northamptonshire, England.
3. Lady Henrietta Frances Spencer was born on 16 Jun 1761 in Althorp Manor, Brington, Northamptonshire, England; died on 11 Nov 1821 in Italy; was buried on 29 Dec 1821 in All Saints, Derby, Derbyshire, England.