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.

In July and August 1973, the Federal Bureau of Investigation (FBI) continued to monitor clashes between United Farm Workers (UFW) members and teamsters, growers, and local law enforcement in Kern County, California. Since 1965, the UFW had launched a series of strikes against farms and ranches in order to gain better working conditions and higher wages. In 1973, UFW lawyers filed civil rights complaints, accusing teamsters and sheriff officers of harassing protesting migrant workers at picket sites near Kovacevich Ranch, Guimarra Ranch, and Nalbandian Ranch.

A July 31 communiqué from the Sacramento field office to the FBI headquarters in Washington, D.C., described confrontations that occurred at Guimarra Ranch and Nalbandian Ranch earlier that day. According to a source whose identity has been obscured, picketers at Guimarra Ranch attacked workers in the field, threw cherry bombs and rocks, and slashed tires on patrol cars.

Subsequent reports document the FBI's investigation into attacks by teamsters against six UFW members at Kovacevich Ranch on June 28. On August 1, the Sacramento field office sent a teletype, which noted that the FBI had ceased its active efforts to locate and interview three of the victims, but had collected 25 statements by witnesses produced by the UFW legal union. On August 6, the Sacramento field office reported its findings from the investigation, which included images of the incident provided by a UFW member.

In an August 15 memo, J. Stanley Pottinger, the assistant attorney general of the Civil Rights Division, asked the FBI to conduct an additional investigation into the actions of the Kern County Sheriff's Office for its alleged failure to intercede in the June 28 attacks.