As the Jacobite threat receded it appears that the maps were forgotten and effectively disappeared from view for about 50 years. Initially, this may have been a deliberate security strategy to avoid them falling into rebel hands. The fair copies had been retained by David Watson. He died in 1761, whereupon these maps were presented to the King. The original protractions appeared to have been held by General Roy himself, who survived a further 30 years. In 1793 these rolls were also presented to George III and held along with the others, uncatalogued, in boxes in the Royal Library at the Queen’s House (Buckingham House).
In 1805, Aaron Arrowsmith, an influential contemporary mapmaker, was contracted to make a map of Scotland. In his preliminary research he discovered that the military had completed a similar commission, fifty years before. He tracked down the maps to the King's collection, where two boxes of rolls were brought out for complete inspection. Arrowsmith was impressed. He searched out and interviewed the five surviving participants in the Survey. David Dundas was now a very senior and distinguished general within the army command, destined to become Commander in Chief a few years later. He surprised Arrowsmith who had not been aware even that a Lowland Survey had been carried out at the time. Dundas assured him that he had done much of it himself! The two then hurried back to Buckingham House where another box with the lowland maps was unearthed. Arrowsmith published his Memoir.. of a Map with an extensive description of Roy’s efforts and first-hand reported details of the 1747 survey.
The Great Map as it now was known, was transferred to the British Museum in 1828, where it was held as part of George III’s Topographical Collection. At some time in the 1830s the material was mounted on linen backed sheets which permitted a composite map of all Scotland. In 1973 the sheets and rolls were moved to the new British Library where they remain today.
The maps were first photographed in 1990. A collaborative project between the British Library and the National Library of Scotland in 2007 digitalised these photographs and cropped, seamed and geo-referenced them. The application is available on line. Thus access to this important historical resource has been simplified and greatly expanded.