Formed January 1, 1800 (24th county)
Barnwell County (20,585), Barnwell (4,653)
The white brick Greek Revival courthouse was erected in 1878 on the square at Main Street and Dunbarton Boulevard. United States Highway 278 is one block to the west. J. Wilden Woodward and Associates are the architects. The facility was enlarged in 1902 and 1921. It features columns and a balcony. An Administration Building was added in 1998. The county was created on January 1, 1800 from Bamberg County as the 24th county. Boiling Spring was the first county seat until 1800 when Barnwell assumed the seat. The county and county seat are named for American Revolutionary War Major John Barnwell. Barnwell County is the birthplace for 2 South Carolina Governors, Johnson Hagood and Joseph E. Harley.
Barnwell County government consists of a sheriff and 7 Council Members. One Circuit Court Judge and Three Family Court Judges serve Barnwell, Aiken, and Bamberg counties. The county is on the southwest border with Georgia. The Savannah River forms its western border. Columbia, South Carolina is northeast and Charleston, South Carolina is southeast of the county. The county center is 5.1 miles North of Barnwell. The county is surrounded clockwise by Orangeburg, Bamberg, and Allendale counties and Georgia and Aiken County.
The area of the county is 557 square miles. It is 30 out of 46 in the state. It ranks 39 out of 46 in population in the state. It has a density of 37.0 persons per square mile making it 38 out of 46 in the state. Barnwell County has 50.5% of its population in its incorporated areas. United States Highway 78 travels through the county from east to northwest from Bamberg County to Aiken County. United States Highway 278 enters from Aiken County, northwest, and exits to Allendale County, south. The county resembles a capital letter P. The City of Barnwell is in the southeast quarter of the county. Barnwell is the county seat and the largest city. It is 22.6% of the county population.
Barnwell
Blackville
Elko
Hilda
Kline
Snelling
Williston