Boston mapmaking was influential in forming Great Britain's perception of the New England colonies. For example, though William Douglass made his map of New England for local consumption, London publisher Thomas Jefferys targeted the English market by adapting it to illustrate a larger struggle for empire. Using Douglass' map as his primary source, Jefferys made additions based on other colonial surveys and added an inset plan of Fort Saint Frederic, a French "incroachment" on Lake Champlain. This map went through several editions and for over 50 years was the pre-eminent map of New England.