Indianola is a city in and the county seat of Sunflower County, Mississippi, United States, in the Mississippi Delta. The population was 10,683 at …Indianola is a city in and the county seat of Sunflower County, Mississippi, United States, in the Mississippi Delta. The population was 10,683 at the 2010 census. In 1891, Minnie M. Cox was appointed postmaster of Indianola, becoming the first black female postmaster in the United States. Her rank was raised from fourth class to third class in 1900, and she was appointed to a full four-year term. Cox's position was one of the most respected and lucrative public posts in Indianola, as it served approximately 3,000 patrons and paid $1,100 annually, then a large sum. White resentment to Cox's prestigious position began to grow, and in 1902 some white residents in Indianola drew up a petition requesting Cox's resignation. James K. Vardaman, editor of The Greenwood Commonwealth and a white supremacist, began delivering speeches reproaching the people of Indianola for "tolerating a negro wench as a postmaster."