Since the late 19th century, when the term “boycott” first made its way to American shores via Ireland, unionized and non-unionized workers have used the tactic as a companion to strikes. The boycott was an accessible, easy way of hitting employers in the “pocket nerve,” as 19th century consumer activists often called it.

It became so popular in the early-to-mid 20th century that unions published lengthy “Don’t Buy” lists of targeted employers. Civil Rights activists also used the boycott to combat Jim Crow segregation, through “Don’t Buy Where You Can’t Work” campaigns in the 1930s and transit boycotts, as in Montgomery, Ala., from 1955 to 1956.

Yet boycotters also faced significant challenges, as business leaders secured injunctions and other restrictions on boycott activities. Most notably, the 1959 Landrum-Griffin Act banned unions' use of the secondary boycott tactic (in which activists would target a business that engaged with a boycotted employer, such as a grocery store that carried a boycotted item).

In the 1960s, Latino workers and organizers — building on these legacies and skirting legal restrictions — helped to revive and reimagine the boycott. In the winter of 1965-1966, in California's Central Valley, the union that would become the United Farm Workers (UFW) added a boycott to its strike against local grape growers. They did so to intensify pressure on unyielding growers and keep organizers and strikers busy in the off season.

For half a decade, striking Mexican and Mexican American farmworkers, their family members and volunteers, many of whom were white college students, followed grape shipments as they headed to supermarkets and community meetings in over 30 major cities across North America. (Because of agricultural exemptions in labor law, the UFW was able to run effective secondary boycott campaigns, to growers' dismay.)

Their efforts reintroduced many American consumers to the boycott and shed light on the plight of those who labored to bring produce to the nation’s supermarkets and kitchen tables. The boycott of grapes became a national cause, drawing support from prominent labor leaders and politicians, such as Democratic presidential candidate Robert F. Kennedy in 1968. This pressure ultimately forced grape growers to sign union contracts in 1970. The UFW has continued to use the tool since then, launching boycotts on lettuce, melons, citrus and wine.