The pivotal event that took place at Boston Harbor in 1773 was the Boston Tea Party. This act of protest was orchestrated by American colonists, particularly the Sons of Liberty, in response to British taxation without representation. They objected specifically to the Tea Act, which granted the British East India Company a monopoly on tea sales in the colonies. As a protest, colonists boarded ships and dumped 342 chests of tea into the harbor. This bold act of defiance escalated tensions between the colonies and Britain, leading to punitive measures by the British and ultimately contributing to the American Revolution.