Aiken County is a county in the U.S. state of South Carolina. As of the 2010 U.S. Census, its population was 160,099. Its county seat and largest city is Aiken. Aiken County is a part of the Augusta-Richmond County, GA-SC Metropolitan Statistical Area. It is mostly in the Sandhills region, with the northern parts reaching in the Piedmont and southern parts reaching into the Coastal Plain.

Augusta (), officially Augusta–Richmond County, is a consolidated city-county on the central eastern border of the U.S. state of Georgia. The city lies across the Savannah River from South Carolina at the head of its navigable portion. Georgia's third-largest after Atlanta and Columbus, Augusta is located in the Fall Line section of the state. According to the U.S. Census Bureau, Augusta–Richmond County had a 2019 estimated population of 197,888, not counting the unconsolidated cities of Blythe and Hephzibah. It is the 123rd largest city in the United States. The process of consolidation between the City of Augusta and Richmond County began with a 1995 referendum in the two jurisdictions. The merger was completed on July 1, 1996. Augusta is the principal city of the Augusta metropolitan area. In 2017 it had an estimated population of 600,151, making it the second-largest metro area in the state. It is the 93rd largest metropolitan area in the United States. Augusta was established in 1736 and is named in honor of Princess Augusta of Saxe-Gotha (1719–1772), the bride of Frederick, Prince of Wales and the mother of the British monarch George III. During the American Civil War, Augusta housed the principal Confederate powder works. Augusta's warm climate made it a major resort town of the Eastern United States in the early and mid-20th century. Internationally, Augusta is best known for hosting The Masters golf tournament each spring. The Masters brings over 200,000 visitors from across the world to the Augusta National Golf Club. Membership at Augusta National is widely considered to be the most exclusive in the sport of golf across the world. Augusta lies approximately two hours east of downtown Atlanta by car via I-20. The city is home to Fort Gordon, a major U.S. Army base. In 2016, it was announced that the new National Cyber Security Headquarters would be based in Augusta.

Columbia County is a county located in the east central portion of the US state of Georgia. As of the 2010 census, the population was 124,035. The legal county seat is Appling, but the de facto seat of county government is Evans.Columbia County is included in the Augusta-Richmond County, GA-SC Metropolitan Statistical Area, and is currently one of the fastest-growing counties in the United States. It is located along the Savannah River.

Orangeburg County is a county located in the U.S. state of South Carolina. As of the 2010 census, the population was 92,501. Its county seat is Orangeburg. The county was created in 1769.Orangeburg County comprises the Orangeburg, SC Micropolitan Statistical Area, which is also included in the Columbia-Orangeburg-Newberry, SC Combined Statistical Area. It is located in the Midlands region of South Carolina. It is the home of South Carolina State University, the only public four-year HBCU in the state of South Carolina. It is also home to Claflin University, the oldest historically black college or university (HBCU) in the state.