I have Crum's in family tree from this area that I'm reseaching as well. This is what I have:
Descending from Darius Crum c.1850's(is time frame I peg him to) from Orangeburg, father was a German immigrant named Krum.
Darius was a plantation owner in Orangeburg, S.C. He had four sons and two daughters by one of his slaves. At this time, I've only the name of his youngest son, which is Dr. William "Demos"thenes Crum, brn. 1859, who grew up on the plantation. He was put through med. sch. by his older brothers and became a physician. He married Bessie Trotter in Charlestown, where he then resided. He was appointed Customs Collector for the Port of Charlestown by Pres. Theo. Roosevelt in 1902, and was US Minister to Liberia in 1909-1912. I have further knowledge of his descendents.
I also have the name of one of his nephews. His name was John Darius Crum brn.1866 in Charlestown. He also became a physician and a surgeon who had a lagre practice in Jacksonville, Florida. If this helps pls let me know. email is firstname.lastname@example.org