Alexander recovers a story that has gone largely untold: how free and enslaved Black people in the United States moved to defend the young Caribbean republic against those determined to keep slavery and white supremacy intact. The arrival of a sovereign Black nation, the book argues, gave Black communities across the African diaspora a source of hope.

Placing Haiti at the center of Black internationalism's history, Alexander traces how the island's independence shaped Black thought and Black action in the United States. Haiti was what white society dreaded most, since it proved that a revolution by enslaved people could end in victory. Black activists responded by claiming a shared identity with Haitians and treating the two peoples' futures as one struggle. The book ties the revolution to a wider pursuit of liberation, justice, and social equality.