The American Revolution was caused by growing tensions between the American colonies and Great Britain. Key events that contributed to war included the Proclamation of 1763 which angered colonists, taxes like the Stamp Act and Sugar Act that colonists felt were unfair without representation, and the Intolerable Acts passed in response to the Boston Tea Party. This led the First Continental Congress to meet in 1774 and Paul Revere's ride warned of the British advance, starting the Battles of Lexington and Concord in 1775 which marked the beginning of the Revolutionary War.