Complex sentence: On 8 July 1920, Brown was discharged from the Marine Corps to accept an appointment to the U.S. Naval Academy, however he left the Academy in September 1922, and re-enlisted in the Marine Corps.
Split into simpler sentences: On 8 July 1920, Brown was discharged from the Marine Corps to accept an appointment to the U.S. Naval Academy. However, he left the Academy in September 1922, and re-enlisted in the Marine Corps.