An officer candidate receives instruction from a sergeant

An officer candidate receives instruction from a sergeant instructor at the end of the Endurance Course (E-Course) at Officer Candidates School aboard Marine Corps Base Quantico, Virginia, July 17, 2019. The purpose of the E-Course is to test the candidate’s physical endurance and their ability to negotiate various obstacles while under duress. The mission of Officer Candidates School is to educate and train officer candidates in Marine Corps knowledge and skills within a controlled and challenging environment in order to evaluate and screen individuals for the leadership, moral, mental, and physical qualities required for commissioning as a Marine Corps officer. (U.S. Marine Corps photo by Lance Cpl. Phuchung Nguyen)