The State Archives (SCDAH) has a wonderfull little pamphlet which
discusses the formation of S. C. distiricts and Counties.

The area that we know as Clarendon County today, became a county in
1868 with the reconstruction of the State Constitution of 1868.
Clarendon District was cut from Sumter District in 1855.  Sumter
District was created from Camden and Cheraws Districts in 1800.

The Districts were subdivided in "management unit" called Counties
they held county courts.(more on the courts later).  Sumter District
was composed of the old counties of Clarendon, Claremont and Salem.
Salem County was part of Cheraws district.

Clarendon district Created in 1855 had the same boundaries as the old
Clarendon county of 1785.

In 1791 Salem County was created from portions of Claremont and
Clarendon Counties and placed in Cheraws District.  Salem was located
adjacent and southwest of Darlington County which became Darlington
District.  Claremont bordered Kershaw, Richland Clarendon and Salem
counties.  A corner touched Old Orangeburg  District.

The county courts were created to hear small cases, common law type of
things.  Debts couldn't exceed 50 pounds, personal damages couldn't
exceed 20 pounds and criminal cases where the penalty wouldn't be jail
time or death.  Legal training was not a requirement for the county
judges.  Justices of the peace heard these cases until 1791.  Then the
General Assembly appointed three judges from each county to handle the
courts.

The archives has another very good pamphlet on the S.C. Court system.
both pamphlets are found on their web site, publications for sale.

Probate court records from 1781 1800 were kept  at the circuit courts.
Cheraws, Beaufort, Orangeburg and Georgetown were destroyed.  Camden,
Ninety-Six and Charleston survived.

Deeds and Wills were kept in Charleston until around 1785.  Afterwards
they were recorded in the Districts.  So Clarendon County of 1785
would have its deeds recorded Lancaster County which supposedly has
deed records back to 1762.  Lexington's county seat of  Camden
supposedly has records back as far as 1791 for deed, court and
probate.

Deborah Byrd