In the 1790s, William Gardner and Thomas Yeakell were employed by the Duke of Richmond to complete a survey of Sussex, but their project came to a halt when the two were drafted into the Board of Ordnance, from which the Ordnance Survey would take its name. Gardner in fact was the Board's chief draughtsman and responsible for many regional maps of Britain in the late eighteenth century. As new material on Sussex became available, however, the Duke of Richmond returned to his great map using data from the official trigonometrical surveying projects being undertaken by the Board. The map was completed by Thomas Gream and published in 1795.

In addition to all the geographical and topographical features found on the land, including towns, cities, villages, roads, woodlands, relief, rivers and notable buildings, much attention is also paid to the coast. Sandbanks, harbour channels and coastal defences are shown in detail, as well as off-shore features, which are often accompanied by annotations identifying "breakers", "hard shifting gravel never dry", "shoals almost dry at low water", and "hard sand and gravel".