When Jens Nielsen was born on 30 September 1829, in Vadum, Ålborghus, Denmark, his father, Niels Jensen Leed, was 58 and his mother, Mariane Andersdatter, was 33. He married Johanne Maria Larsen on 26 December 1851. They were the parents of at least 5 sons and 3 daughters. He lived in Vadum, Kær, Ålborg, Denmark in 1840 and Jetsmark, Hvetbo, Hjørring, Denmark for about 10 years. He was buried in Dunedin, Otago, New Zealand.