Complex sentence: The cook shack had been used by "muleskinners" working to clear land for G.R. or "Gid" Duncan, NEED STUB, INFORMATION ON HIM a partner of land developer Charles Rittenhouse, for whom the school was named.
Split into simpler sentences: The cook shack had been used by "muleskinners" working to clear land for G.R. or "Gid" Duncan. Duncan was a partner of land developer Charles Rittenhouse, for whom the school was named.