… GLC Brown Bag: Karin Zipf, “Field Ghosts:How the American Farmworker Fought Migrant Slavery, then Lost … H2A, 1975-1990” … GLC Brown Bag: Karin Zipf, “Field Ghosts:How the American Farmworker Fought Migrant Slavery, then Lost … GLC Visiting Fellow, Sept.-December 2018, “Field Ghosts: How the American Farmworker Fought Migrant Slavery, then Lost …