At its core, The Warmth of Other Suns is a study of the two Great Migrations which saw Africans Americans move from the Southern U.S. to the Northern U.S. According to Wilkerson, the First Great Migration occurred from 1915 to 1945. The Second - and bigger of the two - Great Migration occurred from 1945 to 1970. Regardless, each Migration occurred because Black Americans needed to go to the Northern states to find opportunities which were sorely lacking in Southern States.
The Warmth of Other Suns is also a biography of four people: Ida Mae, Brandon Gladney, George Swanson Starling, and Robert Pershing Foster. He interweaves their stores, as well as general history, culture, and statistics to explain both why the Great Migrations occurred and what effect they had on the entire United States - not just the Southern states. The Warmth of Other Suns is, at the end of day, an ethnography of the Great Migrations.
