This Labor Day weekend, we invite you to reflect on the larger meaning of four centuries of Black labor and working-class history. The book, Workers on Arrival: Black Labor in the Making of America, by Joe William Trotter, Jr., PhD, professor of history and social justice at Carnegie Mellon University, draws on innovative research and documents the movement of urban Black workers. The book ruminates on the possibilities of addressing the challenges of racial, class, gender, and sexual inequality. Read an excerpt from the Stanford Social Innovation Review.