Throughout the twentieth century Black Americans of all political persuasions were subject to federal scrutiny, harassment, and prosecution. The Federal Bureau of Investigation enlisted black "confidential special informants" to infiltrate a variety of organizations. Hundreds of documents in this collection were originated by such operatives. The reports provide a wealth of detail on "Negro" radicals and their organizations. In addition to infiltration, the FBI contributed to the infringement of First Amendment freedoms by making its agents a constant visible presence at radical rallies and meetings.