As one of 11 kids in a migrant farm worker family, I toiled in the fields of California’s Central Valley under the bleakest of conditions in the 1950s and ‘60s, before Cesar Chavez’s movement offered us any relief. Getting sick or injured or showing symptoms of pesticide poisoning were not options. If they happened, you just worked through it. “If you don’t want to work, there’s plenty of people to take your place,” the foreman or farm labor contractor would say. Little has changed since then in our country, especially for private-sector workers. When her doctor ordered bed rest for Heather,...