Information on American soldiers involved in any war will only be found in bits and pieces on the internet. Details such as you are requesting are usually available in military service files. You should order those here, so you did come to the right place on the internet.

Samuel P. McJunkin served one year with the 4th South Carolina Regiment before joining the Palmetto Sharpshooters, so there are two two service files in his name. McJunkin's file wiyh the Palmetto Sharpshooters reports date and place of death, as well as a claim against the Confederate Treasury filed by his father. The processed form appears in McJunkins's PSS file.