Active for nearly ninety years, its membership and importance varied greatly over time; at its peak, it represented the large majority of stonemasons in the country.
The union was founded in Aberdeen in 1831, and by the end of the decade had fifteen branches including Glasgow and Edinburgh.
Despite this, it had strong financial reserves, and in 1841 it donated £500 to the Operative Society of Masons, Quarrymen and Allied Trades of England and Wales, which enabled it to remain on strike and eventually win a partial victory in a dispute relating to the construction of the Houses of Parliament.
The Aberdeen branch broke away in 1842, forming the rival Northern Union of Operative Masons.
[1] In an effort to rebuild, the union registered with the government in 1879, but it wished to have more freedom to change its rules, and so deregistered just three years later.