Labor lawyer William Carder, whose work for the United Farm Workers included a Christmas Eve 1970 court order that freed UFW leader Cesar Chavez from jail, died of natural causes in Oakland on May 21, the union reported. He was 78.

Carder, a UC Berkeley law graduate in 1966, was an attorney with the National Labor Relations Board before the UFW’s chief counsel, Jerry Cohen, his former law school classmate, recruited him to work in California for what the union described as “subsistence wages.”

It was a time of turmoil in the fields, with Chavez’s UFW organizing nationwide boycotts of crops from California and clashing with the Teamsters Union. In December 1970, a Monterey County judge found the union leader in contempt of court for refusing to call off a boycott of lettuce from growers that did not have contracts with the UFW.

“Boycott the hell out of them,” Chavez called out to his followers as he was led off to jail. About 2,000 union members stood outside the Salinas courthouse, according to a New York Times report.