In December 1922, Hines was assigned as Deputy Chief of Staff of the Army, and became Chief of Staff of the United States Army on September 14, 1924. His army biography states that as Chief of Staff, he "stressed the need for balance in funding and personnel for all parts of the permanent establishment, pointed up the effects of strength deficiencies upon Army capability to meet the provisions of the National Defense Act of 1920, and urged action on housing and promotions to promote personnel retention."