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.

By February 1966, the Federal Bureau of Investigation (FBI) had collected five months-worth of data on the activities of labor leaders, who led strikes against Delano grape growers in Kern County, California. Lasting until 1970, the protests sparked a boycott of California grapes in several states by those who supported higher wages and improved working conditions for farm laborers. Public demonstrations often led to clashes between picketers and local police, grape growers, and working field hands. In some cases, information compiled by the FBI was distributed to law enforcement agencies in order to maintain order and national security.

On February 23, 1966, FBI director received a telegraph sent from Delano by a correspondent whose identity has been redacted. The author of the telegraph requested FBI confirmation of information on persons associated with leaders of the strikes. Among them, the telegraph described NFWA member Wendy Goeple as "publically identified with the Communist Party" and stated that NFWA activist Luis Valdez had made an "unlawful visit to Cuba" in 1964. A third individual, Larry Itliong, was reported as banned by the Filipino government from returning to the country due to "his activities in the Huk uprising."

In a response dated February 26, Hoover replied that the FBI could not provide the information requested in the telegraph because their files were confidential. According to an internal note on the letter, the author of the telegraph had not been identified in FBI files, but individuals mentioned in the telegraph were part of an investigation into communist infiltration of organizations supporting the strikes.