Historians have long realized the US civil rights movement pre-dated Martin Luther King Jr., but they disagree on where, when and why it started. offers new answers in a study of black political protest during the New Deal and Second World War. It finds a diverse movement where activists from the left operated alongside, and often in competition with, others who signed up to liberal or nationalist political platforms. Protestors in this period often struggled to challenge the different types of discrimination facing black workers, but their energetic campaigning was part of a more complex, and ultimately more interesting, movement than previously thought.