Samuel was a son of William John Swainson (1824-1887) & his 'partner' Ruku Te Kauki (1820-1893). His father had about 18 children with Ruku and two other wives.
Samuel worked as a Contractor at Uawa (Tologa Bay) in the 1880's - 1890's. He was Secretary for the Tologa Bay Race Club 1882, also worked for a time as a Shopkeeper, was later employed as a shepherd at Whangara and later at Makauri, Gisborne.

Samuel partnered Louisa Moffatt (nee Freeman) & had 5 known children.
* Louisa had married Charles Moffatt in 1872
their known children (although her bio suggests more)
1873 - 1956 Louisa Emily Moffatt
1876 - 1964 Florence Maud Moffat
Louisa died at Tolaga Bay from a punctured lung when she fell from a horse, 1 day after giving birth to a son (read her bio). Her family sent her sister, Emily Jane Freeman to care for her children (then aged from a day to 19 years) and 14 months later, on 7 July 1890, Samuel & Emily married and had 11 children.

Samuel & Louisa had 5 children
1878 - 1954 Amy Florence Swainson (+Slade)
1882 - 1928 Minnie Esther Swainson (+Sutton +Lane)
1883 - 1943 Frederick Freeman Swainson (+Andrews nee Budge)
1887 - 1972 Daisy Swainson (+Cooper)
1889 - 1958 George William Swainson (+Burbery)
(born 1 day before his mother's death)

14 months after the death of Louisa, Samuel married her sister, Emily Jane Freeman, on 7 July 1890 in Wairoa
note In 19th century NZ, it was illegal for a widower to marry the sister of his wife. The prohibition had its origin in religious belief, but was formalised under British law in the Marriage Act of 1835. However, as Samuel and Louisa had not married (she was already married to Charles Moffatt), this union was legal.
their known children
1891 - 1951 Ernest Alfred Swainson (+Powell)
1893 - 1964 Myrtle Deighton Swainson (+Moran)
1894 - 1967 Herbert Swainson (+Charteris)
1895 - 1974 Ivy Emily Swainson (didn't marry)
1896 - 1902 Lillian 'Ruby' Swainson (aged 5)
1898 - 1971 Alexander Deighton Swainson (+Lewis +McLean)
1900 - 1982 Hazel May Swainson (+McLachlan)
1902 - 1965 Charles Seymour Swainson
1904 - 1950 Doris Swainson (+Vickery)
1906 - 1987 Ida Swainson (+Ropitini)
1908 - 1983 Beatrice Alice Swainson (+Wilson)
1910 - 1998 Samuel Deighton Swainson (+Sutcliffe)

* From Emily's bio (also read her link) .. At the age of 17 years she(Emily) met Mr Swainson and they were married shortly afterwards at Wairoa. Mr Swainson was manager at Mahia for the Ormond properties there and the newly-married couple settled on the peninsula in close touch with the community of whalers, who operated from its beaches and whose trying-pots were for many years objects of interest. She knew 'Happy Jack' well and had many talks with the old mariner concerning his own earlier days, which provided an exciting background to his comparatively sedate life at Mahia.
After some years at Mahia Mr and Mrs Swainson and their young family were transferred to the Whangara Valley to manage properties there for the Ormond family and subsequently Mr Swainson was employed on the Seymour estate. Later again, he was associated with Mr W. D. Lysnar's Okitu property and he then became a farmer on his own account, first at Makauri and later at Waihora, in the Waikohu County. Mr and Mrs Swainson had a family of 11 children and several became prominent in sport.

Poverty Bay Herald, 20 April 1936
SWAINSON - At Te Karaka, on April 19, Samuel Deighton, beloved husband of Emily Swainson; aged 85 years. The funeral will leave Halsman's private chapel, Wi Pere Street, at 2 p.m. to-morrow (Tuesday), for Taruheru Cemetery.

* Mrs Swainson and Family wish to thank relatives and all kind friends and the Waikohu Returned Soldiers' Sports Club for messages of sympathy and floral emblems received during their recent sad bereavement.