The original stated purpose of the Townshend duties was to raise a revenue to help pay the cost of maintaining an army in North America. Townshend changed the purpose of the tax plan, however, and instead decided to use the revenue to pay the salaries of some colonial governors and judges. Previously, the colonial assemblies had paid these salaries, but Parliament hoped to take the "power of the purse" away from the colonies. According to historian John C. Miller, "Townshend ingeniously sought to take money from Americans by means of parliamentary taxation and to employ it against their liberties by making colonial governors and judges independent of the assemblies."