COINTELPRO — the FBI's Counterintelligence Program — began in August 1956 as a covert campaign to "disrupt" the Communist Party and expanded, program by program, to the Socialist Workers Party, the Klan, "Black Nationalist Hate Groups," and the New Left. Over fifteen years the Bureau ran more than two thousand documented operations: forged letters designed to break marriages and provoke gang wars, anonymous tips to employers and landlords, planted news stories, snitch-jacketing of loyal activists as informants, and the systematic use of criminal prosecution as a disruption tool.
The program's own directives stated the goal plainly — to "expose, disrupt, misdirect, discredit, or otherwise neutralize" movements, and to "prevent the rise of a messiah" who could unify Black America. For the prisoner-support movement, COINTELPRO is the indispensable context: many of the era's longest-serving political prisoners were convicted in trials shaped by informants, manufactured evidence, and suppressed exculpatory files, discoverable only years later through FOIA litigation and the Church Committee's investigations.