State highways 3, 70, 64 also pass through the city; SC 64 leads west 6 miles (10 km) to the east entrance of the Savannah River Site, which is a nuclear reservation.

Barnwell County originally stretched from the Savannah River on the west almost to the Atlantic Ocean.

Built in 1832, the South Carolina Railroad connected Charleston to Hamburg, near Augusta, Georgia, upriver on the Savannah River.

The designation of two stops on the railroad led to the development of the towns of Blackville and Williston in the mid-nineteenth century.

Its most distinguished participant was Confederate General Johnson Hagood, who was later elected as governor of South Carolina, serving from 1880 until 1882.

When Union General Judson Kilpatrick was in Barnwell, as part of General Sherman's March to the Sea, his horses were stabled in the Episcopal Church of the Holy Apostles; the baptismal font in the church was used to water the horses.

[11] The climate in this area is characterized by relatively high temperatures and evenly distributed precipitation throughout the year.