The Provosts, a family of sugar-cane farmers in Louisiana, had worked the same land for generations. When it became harder and harder to keep hold of that land, June Provost and his wife, Angie, didn’t know why — and then a phone call changed their understanding of everything. In the finale of “1619,” we hear the rest of June and Angie’s story, and its echoes in a past case that led to the largest civil rights settlement in American history.