Archibald Thomson was born on 7 May 1747; in Westerkirk, Dumfriesshire, Scotland, a hamlet eight miles North of Canobie. The family residence was Nethernoch, a mile west of Westerkirk. (His brothers Andrew and David emigrated to Canada in 1796. The parents of the three brothers were Andrew Thomson, a stone mason, born 1712, and Janet Scott, his wife: they married in 1746). He was the son of
Andrew Thomson and
Janet Scott. Archibald Thomson emigrated in 1773; to Canada. He married
Elizabeth McKay, daughter of
Hugh McKay, on 27 July 1781 at Quebec; or - according to Peter Scarlett - 2/8/1781. Archibald Thomson died on 22 January 1817 at Agincourt at age 69. He was buried at Old St Andrews Cemetery, Bendale, Scarborough.