Commanding General of the United States Army was the title given to the service chief and highest-ranking officer of the United States Army (and its predecessor the Continental Army), prior to the establishment of the chief of staff of the United States Army in 1903. During the American Revolutionary War (1775–1783), the title was Commander-in-Chief of the Continental Army. Between 1783 and 1821, there was no true overall commander for the army. Historians use the term Senior Officer of the United States Army to refer to the individual that held the highest rank by virtue of his date of commission, though the authority they exerted depended on the will of the secretary of war. In 1821, Secretary John C. Calhoun appointed Jacob Brown as the Commanding General of the United States Army, thus establishing the office of Commanding General. The office was often referred to by various other titles, such as "Major General Commanding the Army" or "General-in-Chief".
From 1789 until its abolition in 1903, the position of commanding general was legally subordinate to the United States secretary of war; (senior member of the President's Cabinet), but was replaced by the creation of the statutory chief of staff of the Army by action of the United States Congress in 1903, under the 26th president Theodore Roosevelt (1901–1909).