William, as he was called, was born on 30 June 1842 in Ranum, a son of Carl Georg la Cour (no. 54) and Ida Theodora Wilhelmine la Cour. He started at the Frederiksborg grammar school* in 1854 and at the Roskilde cathedral school in 1857, and graduated from upper secondary school at the latter institution in 1862. During his schooling in Roskilde, he stayed with the pastor of the Sankt Jørgensbjerg church. William passed the university entrance exam* in 1863 and then learned practical forestry in the Odsherred district in 1863-64. He became a candidate forest supervisor in 1868 and was later appointed assistant to the forest supervisor who lived in the Dyrhuset hunting lodge on the Frijsenborg estate. William was appointed interim forest supervisor for that same estate on 1 May 1872, and in November that year his appointment was made permanent. As a practical forester, he was skilled, always on the go, reliable and conscientious in his work. He was considerate towards his subordinates, and they always spoke of him with respect and goodwill and missed him a great deal after he died. From his youth he was physically quite strong, which now and again came in handy, and he was an excellent hunter who never missed. The following amusing little story about him was popular: during a battue hunt at Frijsenborg, the hunting party was walking towards a new site when two shots rang out. “Who was it that fired?” asked old Count Frijs. “It was la Cour,” was the answer, to which the Count remarked, “Well, now we finally have proof that it’s possible for la Cour to miss, since he had to fire twice.” Just then la Cour appeared, and the Count asked him what he had hit. “A buck and a fox, Your Excellency. They’re both lying over there.” Jean married Sophie Amalie la Cour (née Suhr) on 9 September 1872. Sophie was born on 9 November 1840 in Brede, a daughter of Georg Frederik Suhr, a farm-bailiff*, and Sophie Magdalene Worm. She was taken in as a foster child by the people who would later become her in-laws. Sophie died on 23 September 1880, and Jean on on 7 May 1883. (Four children: the Frijsenborg Line.)
