In 1841, Colin, John and Archibald Campbell took up former Canning Downs leases when the Leslie brothers were unable to satisfy government depasture conditions. Naming their tract of land for a district near to their homelands in the south-west of Scotland, the brothers retained Glengallan until 1848 when it transferred to Robert Tertius Campbell of the Sydney-based Campbell Clan financiers. Of the original owners, John Campbell died in California in 1851, his brother Archibald having died earlier in Sydney. Colin Campbell is believed to have remained on the Darling Downs but died in 1853, aged 38, in the Hunter Valley - “the last of three old and well-known colonists”. Robert Campbell sold Glengallan to his partner, C.H. Marshall, in 1852. In September 1854, Marshall took John Deuchar into partnership, trading as Marshall & Deuchar.