Trouble had been brewing in Boston for some time. The city was considered the beating heart of the Patriot cause, and its residents had organized spirited and occasionally violent resistance to British tax policies. When Bostonians responded to 1767’s Townshend Acts with mass protests and riots, the Crown dispatched several regiments of soldiers to police the city. Many denounced the Redcoats as occupiers, and it wasn’t long before locals began clashing with soldiers. On March 2 and 3 of 1770, British troops and a band of Boston ropemakers squared off in a series of street brawls that left one infantryman with a fractured skull. By March 5, the city was awash with rumors that an even bigger confrontation was in the offing. British regulars spoke of their desire to get revenge on the townspeople, and a local minister reported that he heard many Boston men planned on “fighting it out with the soldiers.”

That evening, British Private Hugh White stood watch near the Custom House on King Street. Boston had just emerged from a cold snap, and the roads were blanketed with a foot of snow and frozen ice. As White shivered in his sentry box, a group of British soldiers and Boston townsmen crossed paths on the street in front of him. “There goes the fellow that won’t pay my master for dressing his hair,” wigmaker’s apprentice Edward Garrick yelled towards a British captain. The officer kept walking, but White came to his defense, saying the captain was an honorable man who would settle his debts. When Garrick responded with another insult, White went into a rage. He bashed the colonist in the head with the butt of his musket, dropping him to the ground.

The scuffle caught the attention of bystanders, who rushed to Garrick’s aid and began taunting White and heaving snowballs at him. The private took cover on the steps of the Custom House and loaded his weapon. At some point, the colonists’ stream of insults was interrupted by the sound of church bells in the distance—the traditional warning that a fire had broken out. More men began pouring into the streets, forming a mob of some 50 people. White found himself pinned near the locked door of the Custom House with no means of escape. He began screaming for help.

Word of White’s predicament soon reached British Captain Thomas Preston, an Irishman who was well-liked by most of the Boston citizenry. Preston was loath to send troops into the fray, but he feared for the private’s safety as well as that of the Custom House, which served as the storage site for the Crown’s tax revenues. After some deliberation, he led seven men through the crowd. Upon reaching White, the soldiers formed into a semicircle and used their bayonets to keep the townsmen at bay. The mob had now swelled to several hundred people. Captain Preston screamed at them to disperse and return to their homes, but they responded only with jeers and a barrage of snowballs. Some even dared the soldiers to shoot. “Why do you not fire?” they yelled. “Damn you, you dare not fire. Fire and be damned.”

The sea of humanity stood only inches from the tips of the soldiers’ bayonets, and the troops were being pelted by a steady stream of ice chunks and debris. As the men grew restless, local ropemaker Richard Palms stepped out of the rabble brandishing a wooden stick. “Are your soldiers’ guns loaded?” he asked Preston. The captain answered that they were. “I hope you don’t intend the soldiers shall fire on the inhabitants,” Palms said. “By no means,” Preston replied, pointing out that he was standing in front of his men. Only moments later, someone hurled a wooden club from the crowd, striking Private Hugh Montgomery. The soldier struggled to his feet and raised his weapon. “Damn you! Fire!” he yelled, before discharging his musket.

After the shot rang out, Palms struck Montgomery with his stick and gave Captain Preston a whack on the arm. Exactly what happened next would be the subject of considerable debate. Some said the crowd rushed toward Preston’s men; others claimed the soldiers simply panicked. Whatever the cause, the line unleashed a gruesome volley of musket fire. Two bullets hit and killed Crispus Attucks, a former slave-turned-sailor who had been at the front of the fray wielding a club. Another shot struck colonist Samuel Gray, leaving a hole the size of a fist in his head. Sailor James Caldwell was hit twice and fell dead, and Samuel Maverick and Patrick Carr were both mortally wounded. By the time Captain Preston got his troops to stop firing, five men lay dead or dying and six more were injured.

Boston rattled with tension for the rest of the night. After the shocked crowd scattered from King Street, word went out to colonists in neighboring towns instructing them to take up arms and rush to the city at once. Preston rallied the rest of his troops and prepared for battle. The city seemed on the brink of a general insurrection. Potential disaster was only averted when acting Governor Thomas Hutchinson addressed the people and gave his word that he would conduct a full investigation into the killings. “The law shall have its course,” he promised the furious masses. “I will live and die by the law.” Captain Preston and his eight men were promptly taken into custody. At the urging of the governor’s council, the rest of the British troops later withdrew to Castle Island in Boston Harbor.

Over the next several weeks, Patriots and loyalists published competing narratives of the shootings. Samuel Adams and the Sons of Liberty labeled the dead colonists “martyrs” and helped organize a group funeral attended by thousands. A pamphlet titled “A Short Narrative of the Horrid Massacre” began circulating in the colonies and abroad, and Paul Revere released a now-famous engraving showing the soldiers coldly gunning down a group of defenseless townsmen. Pro-British interests responded with their own pamphlet titled “A Fair Account of the Late Unhappy Disturbance at Boston,” which painted the colonists as treasonous rabble-rousers who attacked “troops who were sent thither to preserve the public peace.”

Although he was aligned with the Patriots, Samuel Adam’s cousin John Adams believed the British soldiers deserved a fair day in court. Putting his reputation on the line, the future president teamed with attorney Josiah Quincy to argue their case. At Preston’s trial in October 1770, Adams asserted that the Captain and his soldiers had acted in self-defense. He characterized the mob as a “motley rabble of saucy boys” that had besieged the redcoats and forced them to react with deadly force. He also found a star witness in Richard Palms, who reluctantly testified that Preston had voiced his intention to hold his fire in the moments before Montgomery was struck by debris. “Facts are stubborn things,” Adams concluded to the court, “and whatever may be our wishes, our inclinations, or the dictates of our passions, they cannot alter the state of facts and evidence.” Preston was found not guilty, and the soldiers were all later acquitted except for Montgomery and Private Matthew Kilroy, who were convicted of manslaughter for their role in setting off the shootings. Both were punished by being branded on the thumb with a hot iron.

John Adams would later describe his work in the trials as “one of the best pieces of service I ever rendered my country,” but the hearings only temporarily cooled the political climate in Boston. Samuel Adams was among the many who denounced the soldiers’ acquittals as a grave miscarriage of justice, and the following year, he helped organize the first of several March 5 “Massacre Day” remembrances. This annual day of mourning kept the incident fresh in the minds of the colonists, and the killings later became a rallying cry during the early days of the Revolutionary War. Even John Adams would eventually acknowledge that “the foundation of American independence was laid” the night shots rang out in Boston.