In 1627 he attracted the attention of Richelieu by a map of Gaul which he had constructed (or at least begun) while only eighteen. Sanson was royal geographer. He gave lessons in geography both to Louis XIII and to Louis XIV; and when Louis XIII, it is said, came to Abbeville, he preferred to be the guest of Sanson (then employed on the fortifications), instead of occupying the lodgings provided by the town. At the conclusion of this visit the king made Sanson a councillor of state.
Active from 1627, Sanson issued his first map of importance, the "Postes de France", which was published by Melchior Tavernier in 1632. After publishing several general atlases himself he became the associate of Pierre Mariette, a publisher of prints.
In 1647 Sanson accused the Jesuit Philippe Labbe of plagiarizing him in his Pharus Galliae Antiquae; in 1648 he lost his eldest son Nicolas, killed during the Fronde. Among the friends of his later years was the great Condé. He died in Paris on 7 July 1667. Two younger sons, Adrien (d. 1708) and Guillaume (d. 1703), succeeded him as geographers to the king.
In 1692 Hubert Jaillot collected Sanson's maps in an Atlas nouveau. See also the 18th century editions of some of Sanson's works on Delamarche under the titles of Atlas de géographie ancienne and Atlas britannique; and the Catalogue des cartes et livres de géographie de Sanson (1702).