The Crescent

If you want to know the true meaning behind South Carolinas' Cresent, you'll get different stories, depending on who you ask. 

The first option you have is that it is a gorget, which was the crescent worn on the caps of the South Carolina revolutionary soldiers.  This version is actually what most people believe.

The other choice seems to make a lot of sense too, though.  In European history, the crescent was a symbol that represented towns founded on the banks of a river loop.  Charleston, or Charlestowne, was the founding city of what became South Carolina, and was established on a "loop" of the Ashley River.  So the image on the state flag could represent the founding city of Charlestowne.

Fountain CAD Diagram