The members of the Cahans Exodus who migrated to Long Cane area near Abbeville, South Carolina, formed the congregations of Little Run, Long Cane and Cedar Creek (later Cedar Spring) churches. Doctor Clark visited this part of his congregation in 1771. He also visited the church in 1779 and 1782. Dr. Clark spent the remainder of 1782 and the greater part of 1783 at Long Cane, Little Run (Little River) and Cedar Spring (organized in 1782). He returned to the north, but moved permanently to Long Canes in 1786.
Doctor Clark eventually settled at Abbeville, South Carolina, and spent the last years of his life there.
"In his old age, nearly thirty years after he had bidden farewell to Ballybay, his mind reverted fondly to the people among whom he had bidden farewell he had spent his early years ... and he addressed to them a Pastoral Letter dated March 15, 1791, which was published after his death. ... Dr. Clark was found dead in his study, on Monday, the 26th of December, 1792, with a copy of his Pastoral Letter spread out before him." Witherow, page 92. Historical and Literary Memorials of Presbyterianism in Ireland (1731–1800) by Thomas Witherow (second series 1880), Chapter LXIV, Thomas Clark, M.D. (1751–1764), Minister of Cahans, county Monaghan.
The Associate Presbyterian (Seceder) Churches formed before 1801 in the Carolina Piedmont include: Providence, Mecklenburg County, North Carolina, before 1790; Long Cane, Abbeville District, South Carolina, in 1779–80, which was united with Cedar Springs in 1786; Little River and Rocky Springs, Abbeville District, South Carolina, before 1801; Tirzah, (Waxhaw), Union County, North Carolina, before 1790; and Joppa, Lincoln County, Georgia. before 1790. "Sketches of Congregations," in The Centennial History of the Associate Reformed Presbyterian Church, 1803-1903, prepared and published by order of the Synod; Charleston, South Carolina (Presses of Walker et al., 1905, pages 407–613).