Dorothy Day, legendary founder of the Catholic Worker Movement, offered crucial support to Cesar Chavez and the farmworkers at several key junctures in their struggle. Most memorably, she travelled to California in the summer of 1973 to get arrested. The UFW, in the midst of a bitter struggle with the Teamsters union, had begun a campaign of mass civil disobedience to protest unconstitutional rulings that blocked their pickets. The arrests did more than that: They made headlines, and they created headaches for local law enforcement authorities because protestors refused to post bail. Farmworkers and their supporters clogged the jails, most famously in Fresno, where a group of religious supporters ended up behind bars for weeks. One of them was Dorothy Day.
Here on the Catholic Worker website is a link to the diary she kept during that July-August 1973 period. And here she is, watched over by two armed deputies:
Earlier that year, she had joined Chavez in New York in support of the boycott. She wrote an account of those events in New York in the spring which you can read at this link.