In 1770 in the city of Boston, capital of Massachusetts Bay Colony, an incident occurred that enflamed anti-British sentiment throughout the Thirteen Colonies. During a time of heightened tension around unpopular taxation and tariffs, British soldiers were sent to protect the appointees of the Crown in Boston. On March 5th, a mob formed around a British sentry who then called out for support. Eight more soldiers joined him as the crowd became increasingly threatening, both verbally and physically. After being struck by a rock-filled snowball, one soldier fired his musket into the crowd and a series of shots from the others followed, instantly killing three men and mortally wounding two others. The rest of the British regiment was called out into a defensive position and the crowd did not disperse until a colonial official promised them that a legal inquiry would take place. The crowd formed again the next day and the British soldiers were forced to withdraw to Castle Island. Soon, charges would be brought against eight soldiers, one officer, and four civilians. The event was depicted in an engraving by Paul Revere, copied from a painting by Henry Pelham. It was not until two years later that Samuel Adams deemed the incident, the Boston Massacre.

After that bloody night, John Adams, a future Founding Father, received a request to play the role of legal counsel for the British soldiers. Despite his own independent views, Adams accepted the case and acted with great integrity to fulfill his duty to the law. Although he fully understood the reasons for the colonial subjects to be angry, he argued successfully that the mob had threatened the British soldiers who in turn defended their own lives. Six of the soldiers were fully acquitted while the other two were found guilty of manslaughter and sentenced to a branding on the hand. The light sentence was earned by a deft legal trick employed by John Adams in which the convicted soldiers were granted Benefit of the clergy because the only definition of "clergyman" was an ability to read from the Bible.

The story of John Adams and the Boston Massacre are an indelible part of early American history. His commitment to providing a fair trial despite his own political views created a precedent for future generations of American lawyers. Years after the event, John Adams' Boston Massacre opinion was that it directly led to the movement for independence from Britain. It is also worth noting the diversity of the victims of the Boston Massacre including a mixed-race slave named Crispus Attucks and an Irish immigrant named Patrick Carr. Unfortunately, Adams used the heterogenous ethnic mix of the crowd to portray them as less controllable and more threatening. Adams singled out Attucks as a provocateur of the conflict who acted with "mad behavior." Attucks would be remembered as the first victim of the Boston Massacre and a hero in African American history. John Adams, and especially his wife Abigail, were opposed to slavery, but it seems that his views on race were mostly in line with the times.