In an effort to induce settlers to come to this area of South Carolina, the Colonial Government in 1736 and again in 1737, set aside two immense grants of land extending for miles along both sides of the Pee Dee River, for the exclusive use of the Welsh Baptist in Delaware who were contemplating removal to this Province. The entire length of Darlington County bounding on Pee Dee River lies within the limits of these two old Royal Grants.
The first village in the entire area and for many years, the only village within what is now Darlington County, sprang up on a bluff on the west side of the Pee Dee River, across from the original settlements and church in the Welsh Neck. It was chosen as the site for the Court House after Cheraws District was created in 1768. In this Court House, in 1774, a Petit Jury Presentment of grievances against the British Crown is among the earliest and boldest declarations of rights in the thirteen colonies. Long Bluff continued to be the seat of justice and commerce throughout the tragic days of the American Revolution.
In 1785, Darlington County was one of three counties created out of old Cheraws District; after some controversy, the site of the Court House of the new county was located on the plantation of John King, Sr. on Swift Creek, about the geographical center of the area. The village thus created was first known as Darlington Court House.
Source - A Brief History of Darlington County, SC
Marlboro, Chesterfield, Florence, Lee and Kershaw counties.