The significant act by the British Parliament in 1773 that incited the Boston Tea Party was the Tea Act. This legislation allowed the British East India Company to sell surplus tea directly to the colonies, effectively undercutting local merchants. American colonists perceived this as another instance of taxation without representation and a threat to their economic autonomy. In protest, patriots, including the Sons of Liberty, famously dumped a large shipment of tea into Boston Harbor on December 16, 1773. This act of defiance escalated tensions between Britain and the colonies, contributing to the American Revolution.