James Dorret's map of Scotland "was a landmark map which was used directly or indirectly for nearly all Scottish maps for the next 40 years" (National Library of Scotland).

Dorrett was an Englishman serving as a valet to the Duke of Argyll, who was given the task of mapping first Argyll and then all of Scotland with the Duke's financial backing. He carried out his own survey for this, his first monumental map of Scotland, supplementing it with information from William Roy's on-going Military Survey of Scotland, completed between 1747 and 1755, and with the latest estate and maritime surveys. His authorship of the Argyll estate survey has been established by the correspondence of John Ainslie, a cartographer who would later publish an important nine sheet map of Scotland which would supersede Dorret's work.

Ainslie wrote dismissively that Dorret was "first a Barber and got into the Argyll family as one of the Duke's valet de chambre, and did take an actual survey of the County or Shire of Argyll... [he] took angles through all Scotland and compiled a map of the Kingdom which may be called a Survey by some people". Ainslie, of course, had every interest in discrediting Dorret's work in favour of his own.

The map was "an immense improvement on anything that preceded it" (Inglis et al.), let down only by the delineation of the Great Glen, Skye and Islay. The Great Glen has a bend in it, despite Dorret having access to sources which would have shown him otherwise. The islands of Skye and Lewis, although not perfect, are drawn with greater accuracy than Dorret's predecessors. The island of Lewis no longer has the flat top given to it since Blaeu's maps of the area, drawing on the maritime charts of Murdoch Mackenzie. Dorret also corrects the shortening of northern Scotland.

NLS EMS.s.640; Inglis, H. G., J. Mathieson, and C. B. B. Watson, The Early Maps of Scotland with an account of the Ordnance Survey, Edinburgh: Royal Scottish Geographical Society, 1934; Tooley, R. V., Maps and map-makers, London: Batsford, 1978.