James Macdonald Calderwood was trained as a mining engineer in Perth, Scotland, and Denver, Colorado, United States. Between 1888 and 1897 he was involved in mining and engineering works in the United States, British Columbia, Mexico, Alaska, and elsewhere, before joining the staff of Fraser & Chalmers in London. He worked in Cornwall and Wales during 1898-1900, and was a mine manager in Hungary in 1900-1901. In 1902 or 1903, just after the Anglo-Boer War (1899-1902), he came to the Transvaal Colony and worked as a consulting engineer to several mining companies. Over the years he was prominently connected with the opening of the gold field in British Bechuanaland (now part of the Northern Cape), the copper mines in the Limpopo Province, and coal, iron and manganese mines near Vryheid, Natal. He became a local director of several companies, including the Messina Development Company, and general manager of the Vryheid (Natal) Railway Iron and Coal Company. He continued working as a consulting mining engineer in Johannesburg to his death in 1947.
Calderwood was a member of the (British) Institution of Mining and Metallurgy, and the American Institute of Mining Engineers. In South Africa he became a member of the British Association for the Advancement of Science in 1905, and of the South African Association of Engineers. He was also a member of the Geological Society of South Africa from 1906 or earlier to at least 1919, and in 1905 took part in the discussion of a paper by F.W. Voit* on gneiss in South Africa. Later he contributed a paper on "The Messina (Transvaal) Development Co., Ltd." to the South African Mining Journal (1912, 21st anniversary number, pp. 218-220). His contribution to archaeology consisted of a paper on "Ancient workings in the Northern Transvaal", which appeared in South African Mines in 1906.
Calderwood was survived by his wife, Lilias S. Donaldson, and two children.