4th Infantry Battalion was formed in April, 1862, when the 4th South Carolina Infantry Regiment was reorganized into a five company battalion. It was assigned to R.H. Anderson's and M. Jenkins' Brigade and saw action in the Battle of Williamsburg, the Seven Days' Battles, and the Maryland Campaign. The unit reported 12 casualties at Williamburg, 9 at Gaines’ Mill, and 38 at Frayser's Farm. On November 11, 1862, it was consolidated into two companies and united with the infantry of Hampton's South Carolina Legion. Major Charles S. Mattison was in command.