The navigation acts were not a direct cause, however using causation, we can say it got the "ball rolling." When the colonies became angry at these navigation acts, the new king (forgot who) made a time of "salutary neglect" in which these previous duties were lowered. It was only until the end of the French and Indian war when this ended (because Britain needed money). The colonist, beginning with the sugar act, became angry because they had existed 50 or so years with lower taxes. This started the anger to begin and heightened resistance right up until the revolutionary war.