The significance of the Boston Massacre in American history lies in its role as a catalyst for colonial unrest and anti-British sentiment leading up to the American Revolution. Occurring on March 5, 1770, the event involved British soldiers firing into a crowd of colonists, killing five. It was widely publicized and depicted as a massacre, fueling outrage among the colonies. This incident helped galvanize opposition to British rule and mobilized public opinion against tyranny. The Boston Massacre became an enduring symbol of resistance and injustice, contributing to the revolutionary fervor that culminated in American independence.