During the 1960s and 1970s, Cesar Chavez
 worked to unionize migrant farm workers by
 (1) seizing the land of the lettuce and grape
 growers
 (2) securing passage of federal legislation to limit
 immigration
 (3) using nonviolent tactics such as boycotts and
 hunger strikes
 (4) urging growers to reduce the workforce
 through mechanization