The primary source document described below, which can be viewed by clicking the thumbnail at right, is part of a 1,434-page file on César Chávez and the farmworker movement compiled by the Federal Bureau of Investigation (FBI) between 1965 and 1973. The FBI's surveillance of Chávez, which paralleled larger efforts to prove that protest groups of the civil rights era had been infiltrated by subversive influences, was unable to uncover any evidence of communism or corruption in the activities of Chávez and his followers.

The FBI's dossier on Chávez was obtained under the Freedom of Information Act (FOIA), which contains provisions that allowed the FBI to withhold portions of the documents from public view. Indeed, many parts—and in some cases, entire pages—have been excised from the files. Nevertheless, the collection provides a compelling window into the efforts of the farmworker movement, as well as the values and methods of the FBI itself.

On October 22, 1965, the FBI's Los Angeles field office sent a memo to headquarters in Washington, D.C., regarding the arrests of 44 picketers involved in the Delano grape strike. On October 19, the protesters were arrested and booked in a Kern County jail after failing to disperse when warned of their "unlawful assembly"; they were later released on bail. A confidential source goes on to report that additional protesters from Los Angeles, Berkeley, and San Francisco were to arrive in Delano that night and the following day; this group would allegedly consist of college professors, students, and ministers. The memo notes that the Delano demonstrations were expected to continue indefinitely and that local law enforcement was fully aware of the situation.