‘Descendant’ and ‘Rosa Parks’ provide new windows into chapters in Black history

Two powerful documentaries explore different aspects of Black history this week, in each case shedding light on misrepresented or under-covered chapters. Presented by Barack Obama’s company under its Netflix deal, “Descendant” examines the discovery of a long-sunk ship that brought enslaved Africans to Alabama, while “The Rebellious Life of Mrs. Rosa Parks” reclaims a figure whose legacy was too often characterized as the product of tired feet.