There is no direct evidence of exactly when the house was built and it can only be guessed from the style and materials that it was probably somewhere about 1760. The early history of the House and lands of Rammerscales is lost in the turbulent years of the 15th century when Border raids and forays made difficult the keeping of records of family life. In those years Rammerscales formed part of the Lands of Holmains and there exists a charter of 1361 whereby David II granted Holmains to the family of Carruthers subject to the overlordship of Douglas, Lord of Galloway and Annandale and in 1426 one Roger Carruthers had confirmed to him in a grant from Douglas the lands of Holmains and Dalton which specifically included Rammerscales.
Despite the Border wars and feuds Carruthers held his estates and though it is not known whether the descent was through the eldest sons the name of Carruthers of Holmains appears in an Act of Parliament of 1587 as being one of the lairds of the Western Marches who could be relied upon to keep order. Also the family appears in Moneypenny’s Chronicle of the same year as one of the 65 lairds and gentlemen re-siding in the Stewartry and Dumfriesshire.
So far as is know for the next one hundred years the lands remained in the possession of the Carruthers family. The next date that can be firmly established is 1687 when Robert Carruthers married Margaret Dalziell and was given Rammerscales from the family estates. The Marriage Stone the commemorated this can be seen today built into the south wing of the stables.
Thirty years later during the Jacobite rebellion of 1745 Robert Carruthers was involved with trying once again to restore the Stuarts. This time those who took part were dealt with severely and it may have been due to this and other causes that ten years later the lands and estates of Rammerscales were disposed of at a judicial sale and ultimately purchased by Dr James Mounsey in 1758.
The Mounsey family came from Skipmyre, a farm in the district, though Dr Mounsey himself had lived for many years in Russia and was the first physician and Privy Councillor for the Empress of Russia. It was about this time that the present square red sandstone House was built in the classic Georgian style of the period, Dr Mounsey, who is reported to have made enemies in Russia, is said to have insisted that every room in the house should have more than one exit so that if he were surprised in one of his rooms by some agent of his enemies he could make good his escape. This is certainly borne out by the unusual number of doorways in the house, although some of these have now been blocked in to form cupboards and alcoves. After the Doctor’s death in 1773 the estate was made over to his eldest son James, though it is doubtful whether he ever lived in the house as laird since he was in the Army and abroad a great deal in consequence. James died in the West Indies in 1780 and was succeeded in turn by two surviving brothers, the last of whom died in 1797 whereupon the estate became vested in his three sisters jointly but, as they were all married and had no wish to live there, the place was sold to James Bell, a sugar merchant of Glasgow for £7,700.