Alexander Caldwell Thomson [also known as A. C. Thomson] was born in Milton, Glasgow, Lanarkshire, Scotland on 19 June 1872 and between 1889 to 1896 was articled to James Donald (1852?-1917) in Paisley and Alexander Skirving (c.1849-1919) in Glasgow. He also attended Paisley School of Art and Glasgow School of Art. From 1896 to 1904 he was employed as chief assistant to James Kennedy Hunter (1863-1929) of Morris & Hunter in Ayr, Scotland. In 1904 Thomson established his own independent practice in Ayr. His work mainly consisted of country houses and schools. He was elected a Licentiate of the Royal Institute of British Architects (LRIBA) in 1912.
Thomson's address was given as Wellington Chambers, Ayr from 1909 and 1921; and Franklin Villa, Ayr in 1912 and 1925. He died in in Ayr, Scotland on 5 October 1925
For a list of architectural projects by Alexander Caldwell Thomson see the Dictionary of Scottish Architects 1660-1980
Directory of British Architects 1834-1914. Compiled by Antonia Brodie, et al. Volume 2: L-Z. London; New York: British Architectural Library, Royal Institute of British Architects/Continuum, 2001