1682:  Colleton County was created. The county was bounded on the north by the Stono River, on the south by the Combahee River, and on the east by the Atlantic Ocean.  There was no western boundary at this time.

1706:  Church Act of 1706 subdivided the SC counties into parishes. St. Paul's Stono Parish was the upper portion of Colleton County, between the Stono and Edisto Rivers.   St. Bartholomew Parish was the lower portion of Colleton County, between the Edisto and Combahee Rivers.

1717:  St. George Dorchester Parish created from the western portion of St. Paul’s Stono Parish.

1730:  St. John's Colleton Parish is created and consists of what had been the islands portion of St. Paul's Stono Parish.

1769: The Circuit Court Act merges Colleton County and Berkley County into Charleston District.   This was bounded by Orangeburg District to the west.

1822: Walterboro became the district seat by a Legislature Act passed in 1817.

1868:  The new South Carolina Constitution does away with the term ‘district’ and replaces it with ‘county.’  Colleton District thus becomes Colleton County.  The county townships were also created in 1868.

1897:  Dorchester County is created from that portion of Colleton County that included St. George Dorchester Parish.  The shrunken Colleton County would now consist of St. Bartholomew Parish and St. Paul's Stono Parish.

1929:  St. Paul's Stono Parish had been merged into Charleston County by 1929. Colleton County would now consist primarily of the old St. Bartholomew Parish. 

References:
SOUTH CAROLINA: A SHORT HISTORY, 1650-1948, David Duncan Wallace, University of North Carolina Press, 1951.