Elder William Hawthorn, Baptist Minister and church planter, was born in Robeson County, NC, in 1762. He moved to Hartford, Ga, in 1806-07 (present-day Hawkinsville). He pastored Cool Springs and Trail Branch Baptist Churches near present-day Cochran, GA from 1807-1822. He was elected as state senator from Twiggs County in 1814. In 1817 he was elected State Representative from Pulaski County (plus some other political ventures). In 1823 he moved to Southwest GA. At the time, the area was still Early County, but he was later active in dividing Early, and the area he lived in became Decatur County. Today the area is Grady County. In 1826 he organized Tired Creek Baptist Church in what is now Grady County, and he served as pastor for 22 years. He died in 1846.
Many of the people who either went with him to southwest Georgia or who followed him came either from Screven County Georgia or from Pulaski County Georgia, but some came directly from Robeson County, NC. Keep in mind, this area had just been opened to white settlement (it had been Creek land until this time). You will still find Clark descendants in Grady County. You might start with Tired Creek Church cemetery and church records.