The term 'Capital of South Dakota' can be solved by two different crossword solutions: Pierre (6 letters) and ESS (3 letters). Pierre is the capital of South Dakota, a state located in the Midwestern United States. It is the second-most populous city in the state and is located on the Missouri River. ESS stands for the Executive and Legislative Studies, which is a program offered at the University of South Dakota in Vermillion. The program focuses on the study of state government and public policy.