Directly in front of the Old State House, encircled by cobblestones, a bronze plaque marks the spot where the first blood was shed for the American independence movement. On March 5, 1770, an angry mob of colonists swarmed the British soldiers guarding the State House, hurling snowballs, rocks and insults. Thus provoked, the soldiers fired into the crowd and killed five townspeople, including Crispus Attucks, a former slave. The incident sparked enormous anti-British sentiment.

Paul Revere helped fan the flames by widely disseminating an engraving that depicted the scene as an unmitigated slaughter. Interestingly, John Adams and Josiah Quincy – both of whom opposed the heavy-handed authoritarian British rule – defended the accused soldiers in court, and seven of the nine were acquitted.