He was born on 1 February 1812 on the Møllemosegård farming estate, a son of Peter David la Cour (no. 10) and Ane Clausine la Cour. Niels Peter worked as farm-bailiff* for Lykkesholm, a farming estate near Odense, from 1831 to 1942. He leased Stenmark, a farm near Grenaa, in 1842 and bought it from his father-in-law in 1845. Niels Peter married Christiane Dorothea la Cour on 29 October 1845. Christiane was born on 14 August 1818 on the Svendsholm farming estate to Otto August la Cour (no. 12) and Ane Cathrine la Cour.
Before her wedding, she worked as housekeeper at Aakær manor for a year and then for eighteen months for Severin Storm, the pastor for Stadil. Niels Peter sold Stenmark in 1855. He had also purchased Sophiesminde, a farming estate near Randers, in 1851, but sold it in the spring of 1855 and bought the Mariagergård farming estate. Niels Peter sold Mariagergård later that year, in the autumn, but died on 7 January 1856, before having moved out. He was an honest and hard-working man, but his extraordinary size and obesity resulted in an early death. After her husband died, Christiane moved to Aarhus and lived there until 1879, when she moved to Odder, where she lived until her death on 9 March 1900. (Six children: the Odder Line.)