<P> Letters from a Farmer in Pennsylvania is a series of essays written by the Pennsylvania lawyer and legislator John Dickinson (1732--1808) and published under the name "A Farmer" from 1767 to 1768 . The twelve letters were widely read and reprinted throughout the thirteen colonies and were important in uniting the colonists against the Townshend Acts . The success of his letters earned Dickinson considerable fame . </P> <P> While acknowledging the power of Parliament in matters concerning the whole British Empire, Dickinson argued that the colonies were sovereign in their internal affairs . He thus argued that taxes laid upon the colonies by Parliament for the purpose of raising revenue, rather than regulating trade, were unconstitutional . </P> <P> In his letters, Dickinson foresees the possibility of future conflict between the colonies and Great Britain, but cautions against the use of violence until "the people are fully convinced": </P> <P> If at length it becomes undoubted that an inveterate resolution is formed to annihilate the liberties of the governed, the English history affords frequent examples of resistance by force . What particular circumstances will in any future case justify such resistance can never be ascertained till they happen . Perhaps it may be allowable to say generally, that it never can be justifiable until the people are fully convinced that any further submission will be destructive to their happiness . </P>

Who authored the letters from a farmer in pennsylvania in protest to the revenue act of 1766