Johann (John) Gottlieb Wilhelm Leipoldt, land surveyor, was a son of the Rhenish missionary Christian Friedrich Leipoldt and his wife Anna M.C. Leipoldt (born Esselen), an older brother of the author and poet C. Louis Leipoldt*, and a younger brother of Miss Luise F.C. Leipoldt*. The family came to the Cape Colony in 1879 and resided in Clanwilliam from 1884. Johann served as an artillerist under General Lucas Meyer during the Anglo-Boer War (1899-1902). After the war, in 1905, he passed the Survey Certificate examination of the University of the Cape of Good Hope. Two years later he married Constantia Petronella Hendrika van Niekerk, with whom he had a son and a daughter.
Leipoldt became a member of the Geological Society of South Africa in 1911. In 1913 he was appointed as an instructor at the Military School of the South African Defence Force, which was then at Tempe, near Bloemfontein, with the rank of captain. During World War I (1914-1918) he was appointed chief intelligence officer with the rank of major in May 1915 and served on the staff of General Louis Botha during the South West Africa (now Namibia) campaign. Subsequently he served in East Africa, but was returned to South Africa towards the end of 1916 suffering from malaria. Upon his return to work he was ordered to make a survey of Saldanha Bay and its hinterland, and report on the possible use of the bay as a sea base by an enemy. He mapped the bay at a scale of 1:50 000 and completed his report in October 1917
After the war, in June 1919, he was selected to serve on the South West Africa Boundary Commission, which settled the border between that territory and Angola. In May 1920 he was appointed as instructor at the Military School, which had been relocated at Roberts Heights, Pretoria. However, he first took leave to travel to the source of the Kunene River to investigate the views of Professor E.H.L. Schwarz* on the water capacity of the river and of Etosha Pan, returning to Pretoria only in January 1921. From August to September that year he was sent on another expedition to investigate Schwarz's proposed Kalahari irrigation scheme. A third mapping and reconnaissance expedition for the same purpose, to parts of Northern Rhodesia (now Zambia), Angola and South West Africa, took place during May to June 1922. It has been claimed (SESA, 1970-1976) that he and others organised these expeditions to search for the supposed treasure of Lobengula, chief of the Matabele.
Leipoldt resigned from the military in April 1923 to become a surveyor in the Cape Province. He first worked for the Trigonometric Survey in Cape Town, and later went into business with his son and daughter, establishing the firm Leipoldt & Leipoldt in Springbok, Northern Cape. During the nineteen-twenties he published several papers in the South African Survey Journal, dealing with 'A South African grid' (1925, Vol. 1(5), pp. 250-253), 'The Orange Free State topographical survey' (1927, Vol. 2(5), pp. 224-228), 'The Wild and Zeiss theodolites' (1927, Vol. 1(7), pp. 319-326), 'The Wild geodetic theodolite' (1927, Vol.1(8), pp. 360-362), and 'The higher education of surveyors' (1928, Vol. 3(19), pp. 88-89). During the next decade he contributed two papers, 'Observing with the Wild and Zeiss theodolites' (1937) and 'Errors of the parallel-plate micrometer' (1938) to the Survey Review.