10th Regiment, South Carolina Militia
Joseph H. Crute, Jr.'s book, "Units of the Confederate States Army", contains no history for this unit. This regiment most likely transferred into another regiment or was combined with another regiment to create a new regiment, or is another name for an existing regiment. Looking at the service records of the soldiers may give clues to the different regiments they may have served in.
"South Carolina Reserve and Miscellaneous Units in the War of the Rebellion", lists the 10th Regiment, South Carolina Militia as a regiment, but no other information is given.
Companies in this Regiment with the Counties of Origin
Men often enlisted in a company recruited in the counties where they lived though not always. After many battles, companies might be combined because so many men were killed or wounded. However if you are unsure which company your ancestor was in, try the company recruited in his county first.