As is common the case with people of color, children and women during the revolutionary era, it is not always easy to find primary sources related to individual acts of colonial protests. Had the event that became the Boston Massacre not ended in bloodshed, it's very likely we never would have heard of Crispus Attucks. In fact, we know very little about him to start. I'd like to refer to this post of mine where I talk about Attucks and put him in the context of the political protests of the 1760s. If you have any follow-up questions or a more specific question about African Americans in revolutionary Boston, I would be happy to answer them.