This is the shocking true story of the Black American codebreaking unit whose top-secret work led directly to the end of the Cold War. Facing the global threat of a rising Communist world power in the aftermath of World War II, the US employed hundreds of Black Americans to speed read Russian communications and gather essential information on the US's most dangerous nuclear rival. The result was the creation of a segregated civilian codebreaking unit known as the Traffic Processing Division - The Plantation. Despite wage discrimination, gruelling hours and harsh conditions, the Plantation's 100 college-educated Black women made invaluable breakthroughs in United States' Soviet intelligence, even as the backlash against civil rights eroded their democratic freedoms at home. Sarah Valentine tells their remarkable story in full for the first time. Paying long overdue tribute to these little-known Black cryptologists' critical contributions to national security during the civil rights era and the Cold War.