Long Before Serving as the 33rd President of the U.S, Harry S. Truman Served His Country on the Front Lines of WWI

“My whole political career is based on my war service and war associates.” – Harry S. Truman

Long before serving as the 33rd President of the United States, Harry S. Truman served his country on the front lines of World War I. Truman is the only US president to see combat during the First World War. His war experience affected the course of his life and influenced his rise to the presidency in two important ways: he discovered a leadership ability he hadn’t known that he possessed, and he garnered a significant political base that supported him in his rise though political ranks.

When the United States entered World War I in April 1917, Truman was 33 years old and living in Independence, Missouri. He was working on his family’s farm and was also a member of the Missouri National Guard, having previously served from 1905 to 1911. When the U.S. declared war, Truman rejoined the Guard and helped organize Battery F of the 129th Field Artillery Regiment, part of the 35th Division.

Harry S Truman’s military identity card from the American Expeditionary Forces.

Truman was elected first lieutenant, and his unit trained at Camp Doniphan, near Fort Sill, Oklahoma. There, he gained a reputation for discipline, precision, and a fair but firm leadership style. He studied artillery tactics intensely, determined to do well despite lacking formal military education.

By mid-1918, as the division prepared to go overseas, Truman was promoted to captain and given command of Battery D — a unit notorious for its poor discipline and low morale. The men had run off previous officers, but Truman won their respect through a mix of strict order and genuine concern for their welfare. His leadership turned the unruly battery into one of the most reliable in the regiment.

Truman and his men arrived in France in April 1918. Battery D first saw combat in August 1918 in the Vosges Mountains in Alsace-Lorraine. During a German shell attack, many of his men fled, but Truman stood his ground, cursing the fleeing soldiers until they returned to their posts, an incident he later referred to as the “Battle of Who Run.” This decisive display of leadership won him the enduring loyalty of his men.

Battery D participated in the Saint-Mihiel Offensive and the massive Meuse-Argonne Offensive, providing artillery fire support. Notably, Truman defied an order by firing on German guns outside his designated sector to protect an American infantry unit, a move that saved lives.

When the Armistice was signed on November 11, 1918, Truman’s unit was near the front. He remained in Europe for several months as part of the occupation force before returning home in spring 1919. He left the service with the rank of captain, a title he proudly used for the rest of his life.

Captain Harry S. Truman, Battery D, 129th Field Artillery Regiment.

Portrait of Truman in September 1917.

Harry S Truman wearing his uniform, taken in France during World War I in 1918.

Captain Harry Truman served in France during WWI.

Captain Harry S. Truman, Battery D 129th Field Artillery, sitting on a horse at Camp Coetquidan, Brittany, France, in July, 1918.

The future President sports a rare mustache at Army Reserve camp.

Captain Harry Truman (2nd from left) commanded Battery D, 129th Field Artillery, 60th Brigade, 35th Infantry Division in World War I, ca. 1918.

Officers of the 129th Field Artillery, at regimental headquarters at Chateau le Chanay near Courcemont, France, March 1919. Captain Harry S. Truman is pictured in the second row, third from the right.

Harry S Truman (third from right) and some men of Battery D, 129th Field Artillery, 35th Division, United States Army in France after the end of World War I, ca. 1919.

First Lieutenant Harry Truman (14th from left) enjoying a soft drink with fellow officers, ca. 1917.

Battery D at Camp Mills, New York. Captain Harry S Truman is in the front row, April, 1919.