Adna R. Chaffee, Jr.

Adna Romanza Chaffee Jr. (September 23, 1884 – August 22, 1941) was an officer in the United States Army, called the "Father of the Armored Force" for his role in developing the U.S. Army's tank forces.

Chaffee was born in Junction City, Kansas, on September 23, 1884 to his father, Lieutenant General Adna R. Chaffee, and mother, Annie Francis Rockwell. He was commissioned as a Lieutenant of Cavalry in 1906 following his graduation from the United States Military Academy. He was 31st out of 78 pupils in his class. Chaffee learned to ride on horseback from a young age, and would later receive recognition as "the Army's finest horseman".

Upon his father's death in 1914, he became an Hereditary First Class Companion of the Military Order of the Loyal Legion of the United States.

In World War I, he was an Infantry Major with the IV Corps during the Battle of Saint-Mihiel. As a Colonel, he later served with the III Corps throughout the Meuse-Argonne Offensive.

Following the war, he returned to his Regular Army rank of Captain of Cavalry and became an instructor at the General Staff School and the Army School of the Line at Fort Leavenworth. During the 1920s, he helped develop the armor concepts and doctrine of the future. He predicted in 1927 that mechanized armies would dominate the next war and assisted in the first program for the development of a U.S. Army armored force. Assigned to the 1st Cavalry Division in 1931, he continued to develop and experiment with armored forces, thus becoming the leading American advocate of mechanized warfare.

In 1938, he assumed command of the reorganized 7th Cavalry Brigade, the Army's only armored force. Chaffee battled continuously during the prewar years for suitable equipment and for establishment of armored divisions. With the collapse of the French Army in June 1940, Chaffee's 1927 predictions of the importance of armored forces in modern warfare were confirmed.

Chaffee died of cancer on August 22, 1941, in Boston, Massachusetts.

The M24 Chaffee light tank is later named after him.

Fort Chaffee, Arkansas, near Fort Smith, Arkansas, is named in his honor.