Beneath a searing Louisiana sun, a crowd gathers on a former sugar cane plantation to commemorate Juneteenth, a holiday celebrating the end of slavery in the United States. Rows of unmarked graves stand nearby—believed to be the resting place of those who’d been enslaved on the plantation. A few people, clad in face masks, hold up a banner: Honoring Our Ancestors. Another sign, staked into the grass, is aimed not at the past, but at the future: FORMOSA: YOU ARE NOT WELCOME HERE.