Most historians begin with a large argument or theory, then attempt to demonstrate its relevance within a specific context. Louis Masur reverses this interpretive process, beginning with a very specific incident – in this case a racially charged moment in Boston in 1976 – then spreading outward to trace its origins, resonances and implications for the larger story. In order to do this well you need to know how to tell a story and write uncommonly well, both qualities that Masur possesses in abundance. In my judgment, he is the best there is at what he does.