John Thornton was a leading English chart-maker, active between 1667 and 1708. He was apprenticed to John Burston in the Draper’s Company in 1656; at the time, and despite the name, the Draper’s Company was the epicentre for the leading makers of manuscript charts in England, with Burston a prominent figure in the “school” and Thornton emerges as a skilled practitioner both as a maker, and possibly as an engraver. He described himself as Hydrographer to the East India Company and Hydrographer to the Hudson Bay Company, although he is not recorded as such in the records of either company.
He was the first member of the “school” to make the transition from manuscript to printed charts, publishing three charts relating to the Americas or Atlantic in 1673, but his career path changed dramatically in 1677 when he entered into partnership with a group, including William Fisher, to assist John Seller in continuing his chart publishing business. When the
partnership ended Thornton retained some of Seller's materials, and moved firmly into publishing.
The core of his business was chart publishing, the most important of his atlases being the ‘English Pilot. The Fourth Book’ (1689), the first English sea atlas devoted to the English colonies in North America and the West Indies, published jointly with William Fisher, and much reprinted. He also published ‘The English Pilot. The Third Book ... the Oriental Navigation’ (1703), the first printed sea atlas of southeast Asia and the East Indies.
However, Thornton went on to publish some of the most important maps of the English American colonies of the period: with Robert Greene ‘A Mapp of Virginia Mary-Land, New Jarsey, New York, & New England’ (1679); and with John Seller ‘A Map of some of the South and Eastbounds of Pennsylvania’ . He collaborated frequently with Thomas Holme, producing ‘A Portraiture of the City of Philadelphia’ , ‘A New Map of the English Empire, in the Continent of America’  and ‘A Map of the Province of Pennsilvania’ .
Above 40 manuscript charts and somewhat over 100 printed charts and maps by Thornton survive, this corpus earning him the accolade “the most competent and distinguished chart-maker in England
He was succeeded by his son Samuel (c.1665-1712) on his death in 1708, but Samuel died shortly after, and the stock was acquired by Mount and Page.