Black Radical reclaims William Monroe Trotter (1872–1934) as a seminal figure whose prophetic yet ultimately tragic—and all too often forgotten—life offers a link from Frederick Douglass to Black Lives Matter. Kerri K. Greenidge renders the drama of turn-of-the-century America, showing how Trotter, a Harvard graduate, a newspaperman and an activist, galvanized black working-class citizens to wield their political power despite the virulent racism of post-Reconstruction America. Situating his story in the broader history of liberal New England to “satisfying” (Casey Cep, The New Yorker) effect, this magnificent biography will endure as the definitive account of Trotter’s life, without which we cannot begin to understand the trajectory of black radicalism in America.