In the early 1940s, Elroy Williams attended third grade in a simple wooden building in rural Bastrop County. The structure lacked indoor plumbing and relied on a wood stove for heat. But the walls were lined with windows that let in plenty of light and could be opened in the warmer months to create a pleasant cross breeze. The students’ parents brought firewood to the school in winter, and some of the older kids, in seventh and eighth grade, helped cut it to size. This was a Rosenwald school—one of nearly five thousand schools built between 1912 and 1937 in a historic initiative that transformed public education for African Americans in the rural South.Williams’s future wife, Sophia, went to another Rosenwald school a few miles…