Last week American swimmer Simone Manuel became the first African-American woman to win an individual Olympic medal when she took gold in the women’s 100-meter freestyle. After the race, she said: “This medal is not just for me. It’s for a whole bunch of people who came before me,” and then mentioned the names of other African-American Olympic athletes. Her story and her comments put the long history of racial segregation of swimming in the United States right in front of Americans where they couldn’t ignore it: On live broadcast television. Morning Shift talks to historian Isabel Wilkerson about swimming and racial discrimination from segregated public pools to pools being drained because black celebrities swam in them to acid being thrown into the water. Wilkerson is author of The Warmth of Other Suns, a history of the Great Migration.