John may have been born 17 April 1765 to John and Esther Hall, or 28 December 1770 to John and Hester Hall. Both were baptised at St Marylebone Parish Church, London.
Mary may have been the daughter of Christopher and Sarah Callis who had children baptised at the same church, namely Thomas (1770), Elizabeth (1775) and Sarah (1781).
They were married at St Marylebone Parish Church, 13th February 1792.
Their children were all baptised at this church:
Edmund Hall was baptised 31 March 1793|
Mary Calais Hall was baptised 5 June 1796
Susanna Hall was baptised 9 September 1798
Ann Hall was baptised 3 August 1800
Sarah Hall was baptised 8 December 1802
Elizabeth Margaret Dutton Hall was baptised 23 December 1804. She married Thomas Saville
Jane Hall was baptised 19 November 1809
John Hall was baptised 11 March 1810