In pursuit of his foremost goal, full and equal citizenship for African Americans, Peter Humphries Clark (1829–1925) defied easy classification. He was, at various times, the country's first black socialist, a loyal supporter of the Republican Party, and an advocate for the Democrats. A pioneer educational activist, Clark led the fight for African Americans' access to Ohio's public schools and became the first black principal in the state. He supported all-black schools and staunchly defended them even after the tide turned toward desegregation. As a politician, intellectual, educator, and activist, Clark was complex and enigmatic.

Though Clark influenced a generation of abolitionists and civil rights activists, he is virtually forgotten today. America's First Black Socialist draws upon speeches, correspondence, and outside commentary to provide a balanced account of this neglected and misunderstood figure. Charting Clark's changing allegiances and ideologies from the antebellum era through the 1920s, this comprehensive biography illuminates the life and legacy of an important activist while also highlighting the black radical tradition that helped democratize America.