sentences:  Map historians have understandably been interested in why a physician and botanist who had shown no previous interest in map making should make such a large and detailed map.Until recently, historians have argued that Mitchell was upset by the lack of interest shown by politicians in London about colonial affairs and so set out to warn them about the dangers posed to the British colonies by the French.Mitchell did so, on his own initiative, by making a first map of North America in 1750, which he then showed to the politicians he knew through his botanical and gardening activities.