John Chapman was a land surveyor brought up in the village of Dalham in Suffolk who later came to work in London with Mrs Mary Ann Rocque, widow of John Rocque, the highly influential surveyor, engraver and cartographer. Chapman had previously been involved in producing county maps of Durham, Staffordshire and Nottinghamshire. He died the year after his Essex map was published. Peter André was of Huguenot descent, like many others involved in county surveys, and had gained experience of county surveys with his involvement in the publication of a map of Surrey. In summary the two surveyors were unusually proficient in surveys of large areas of land, such as counties; this probably explains why their Essex map is of exceptional accuracy and beauty.