The principal cause of the American Revolutionary War was a combination of increasing tensions over British taxation and lack of colonial representation in Parliament. As Britain imposed various taxes, like the Stamp Act and Townshend Acts, colonists protested vigorously, arguing against "taxation without representation." Other factors included the desire for greater autonomy and resistance to British colonial policies, especially after events like the Boston Tea Party. These grievances sparked widespread dissent, laying the groundwork for revolutionary sentiment. The culmination of these issues catalyzed events leading to open armed conflict, ultimately resulting in the colonies' quest for independence.