Major General John A. Lejeune was a prominent figure in the United States Marine Corps, serving from 1880 to 1942. He is best known for his leadership during World War I and for his role in establishing the Marine Corps as a key fighting force. Lejeune was the 13th Commandant of the Marine Corps and is remembered for his contributions to military strategy and training. Lejeune was also instrumental in the development of the Marine Corps Base Camp Lejeune in North Carolina, which was named in his honor. His legacy includes the promotion of the Marine Corps motto, "Semper Fidelis," emphasizing loyalty and commitment.