S.C. Code § 4-3-200
Dorchester County is composed of all that territory formerly a portion of Colleton County comprised in the townships of George, Koger, Carn, Burns, Givhans, Dorchester and that part of Collins township formerly in said county of Colleton lying north of the public road leading from Parker's Ferry, upon the Edisto River, to a public landing known as Lowndes' Landing, upon Rantowles Creek, and all that portion formerly of Berkeley County included within the following lines, to wit: from the intersection of the county line between Colleton and Berkeley Counties with the run of Four Holes Creek a straight line to a point upon Saw Mill Branch one mile northeast of the Southern Railway; thence along said branch to the former Colleton County line, and thence back to the starting point along the former line of division between Colleton and Berkeley Counties. And is bounded northeast by Berkeley County, from which it is separated by the Four Holes Swamp from the intersection of said swamp with the old district line (drawn from Nelson's Ferry, on the Santee River, to Matthews' Bluff, on Savannah River) to the intersection of the run of said swamp with the old county line between Colleton and Berkeley Counties; and by a straight line running thence to a point upon Saw Mill Branch one mile northeast of the South Carolina and Georgia Railroad, and thence along said branch to the old division line between Colleton and Berkeley Counties; and thence by said old division line to the point where said line intersects the division line between Charleston and Berkeley Counties; on the southeast by Charleston County, from which it is separated by the old division line between Charleston and Colleton Counties to Lowndes' Landing, on Rantowles Creek; southwest by Colleton County, from which it is separated by the public road leading from Lowndes' Landing, on Rantowles Creek, to Parker's Ferry, on Edisto River; and thence by the said river to the intersection of said river with the old district line down from Nelson's Ferry, on Matthews' Bluff; and on the northwest and northeast by Orangeburg County, from which it is separated by said last-mentioned district line.
S.C. Code § 4-3-200