 So documentary evidence that the three counties were within St. Mark's Parish (formed in 1757 from Prince Frederick's Parish, Craven County) in Camden District (formed 1769) derives from family genealogies and legislative records.On 19 December 1855, a legislative act was passed partitioning Sumter District by forming Clarendon District, with the same boundaries as defined for Clarendon County in 1785.When effectuated in 1857, a northeastern part of Sumter District (formerly in Salem County) was also separated in the partition (the area east of a line drawn from the northernmost point of old Clarendon County continued north-northeasterly to a point on the boundary line with Darlington District (Sumter County's northeastern cornerpoint abutting Florence County since 1888).