Thursday marks the 250th anniversary of the Boston Massacre, during which five people were killed in a face-off between American colonists and British soldiers. More than two centuries later, there is still a lot of misunderstanding surrounding the incident. WGBH Morning Edition host Joe Mathieu spoke with author and historian Anthony Sammarco about the infamous moment that sparked the American Revolution. The transcript below has been edited for clarity.

Joe Mathieu: We always love seeing you because you always tell a great story, and this is one for the ages. March 5, 1770. It was a cold night downtown [with] an agitated crowd of Bostonians fixing for a fight. Accurate so far?

Anthony Sammarco: It is accurate. I think in a lot of ways, people had to realize this was something that was building up over the last decade. Boston had been occupied since 1768 by the British troops. And the consequence was, it wasn't just the fact that they occupied the city, but it was also the fact that they were in some ways, again, another sense of oppression. And I think in a lot of ways, many of the colonists and people that were part of this crowd of Bostonians were seeking either revenge or basically to create what eventually did become the massacre.

Mathieu: We use the term "massacre," and if you look it up in the Webster's dictionary, "the act or instance of killing a number of usually helpless or unresisting human beings." That's what happened here? Five people died.

Sammarco: It wasn't, really. In a lot of ways, when I teach this course at Boston University, it's something that I make my students understand what a massacre truly is. But it was the master of propaganda, Sam Adams, who would actually say that it was a massacre. It didn't matter what the number was, it was the term that was used. And whether it was in Massachusetts or it was one of the 13 colonies, I think the word "massacre" created this sense of mass killing.

And I think in a lot of ways, people in Boston had to realize that it wasn't just the fact of Sam Adams, who really was somebody who wrought what became the Boston massacre, but it was people who basically realized that their lives were at stake, and the taxation that had actually taken place in the 1760s with the Townshend Acts [and] the occupation of Boston by the British soldiers, this was something that was a culmination of events.

Mathieu: Most people are familiar, Anthony, with the famous engraving by Paul Revere, showing what basically looks like a firing squad shooting into a well-dressed crowd [that] just happened to be there. How many things are wrong with that image?

Sammarco: Well, there's a lot of things wrong with it. One of the concepts is: Paul Revere, who was a copper plate engraver, was also a plagiarist. The first engraving was done by Henry Pelham, who was the stepbrother of John Singleton Copley, one of the best-known painters in all of the Americas. And the concept here was that he produced something, but Paul Revere took it one step further. Not only did he show the British shooting upon the people of Boston, but he also calls the Customs House that was on King Street — or what today we call State Street — was called "Butcher's Hall." So I think in a lot of ways, Paul Revere wasn't just a son of liberty. He wasn't just a silversmith, a goldsmith [and] he wasn't just a dentist. He was also, again, another one of the major propagandists of the Revolutionary War period.

Mathieu: Do we believe the redcoats actually feared for their lives that night? Was that an act of self-defense or not?

Sammarco: I would assume that they did, because the records of the period show that many of the people in Boston were throwing not just snowballs, but snowballs with rocks in them. They were throwing cudgels and all sorts of things at the British soldiers.

And the surprising thing was, as the crowd gathered — and they said there were 300-400 people, which was a huge crowd in Boston at that time — that the bells of Boston began to ring in the meeting houses. That was only done when there was a sense of either calamity or a fire. And in that instance, many people began to think that there was actually a fire in the city. One wouldn't know unless that person was in the area of King Street. And many people said that they heard the word "fire" screamed by somebody in the area. I think at that point, the British soldiers literally fired upon the colonists.

The surprising thing was, and I use this term hesitantly, but they were rabble. These were people who were itching for a fight. And I think in some ways, I don't think they ever assumed the British would actually fire upon them. When they did, three people were killed outright, a fourth person died the next morning and then one a week later. And I think one had to realize it was a mélange of people that included Crispus Attucks, an escaped slave who actually was working on the waterfront, but it also included an Irish immigrant and three colonists. So you had to realize it was really a cross section of Boston at the time, but it was also something that surprised me, that the man that actually defended the British troops was John Adams, who became our second president of the United States. And it was Robert Treat Paine who would actually defend the colonists.

Mathieu: He made these people sound like a bunch of drunks out looking to start a fight.

Sammarco: Well, I think in many ways they probably had imbibed, but the concept was whether they were drunk or not, I think it was something that Sam Adams took that one step further and by calling it the Boston Massacre, incited shock and awe in people not only across the colonies, but also in Europe. What really happened?

And then when one saw not only Henry Pelham's, but later Paul Revere's etching, one began to realize in some ways whatever it was, it was horrific. And even though, and it sounds terrible, only five people died — it's still terrible that anyone died — but it was something that people began to realize what it was meaning. It was the spark that ignited the Revolutionary War.