Alexander9 Sanderson was born 5 October 1863 in Morpeth NSW, and died 24 September 1937 in Sydney NSW. He married Sarah Jane Dent 21 February 1893 in St Savient's and St Jude's Surry Hills Sydney NSW, daughter of Thomas Dent and Mary Craine. She was born 12 December 1863 in Adelong NSW, and died 14 February 1926 in Sydney NSW.
Alexander was the second born and eldest surviving son. He was seven or eight years old when the family moved to Wallabadah NSW and would have learnt farming and animal husbandry from helping out on the farm as a youngster. In 1891 when his father, Henry Sanderson, made his will, Alexander and his brother Lancelot were in Queensland. They were resident at Wallabadah NSW in 1893 when Henry died. Alexander did not stay at 'Sunnyside' but purchased his own property at Walgett NSW -'Combadery, a wheat and sheep farm. His father, Henry died in the January of 1893 and Alexander married one month later in the February and it was to 'Combadery' that he bought his new wife Sarah Jane Dent. They raised five children, two sons and three daughters. In 1926, aged 62 years Sarah died in a private hospital at Stanmore Sydney NSW and was buried in Rookwood cemetery Sydney NSW. Alexander continued to live in Walgett NSW and died in 1937 aged 73 years and the body was brought to Sydney NSW for burial beside his wife at Rookwood NSW.