His early training was as an illustrator and draftsman, and his influences were the master garden designers Dezallier d'Argenville and Jean-Baptiste Alexandre Le Blond.
Sauthier migrated to America in 1767 at the request of British royal Governor of North Carolina William Tryon.
Sauthier surveyed and created maps of Bath, Beaufort, Brunswick Town, Cross Creek (now Fayetteville), Edenton, Halifax, Hillsborough, New Bern, Salisbury, Wilmington, and the Camp and Battlefield of Alamance.
Original copies of Sauthier’s maps are archived in the King George III's Topographical Collection at the British Library in London, the Public Record Office in London, the North Carolina Division of Archives and History in Raleigh, North Carolina, and the Clinton Collection at the William L. Clements Library at the University of Michigan.
General Percy retained Sauthier on his staff when he commanded the British forces holding Rhode Island.