Multiple studies have demonstrated that the improved extent of resection for patients with glioma is associated with improved survival. The use of intraoperative electrophysiology cortical mapping to demonstrate function became a standard of care in modern neurosurgery and an indispensable tool to achieve the goal of maximal safe resection in tumor surgery. In this study, we review the brief history of intraoperative electrophysiology cortical mapping from the first cortical mapping study back in 1870 to the innovative tool of broad gamma cortical mapping used today.