Duke headed the education department at Farmville Normal School (later renamed Longwood University) until 1917, when he was appointed as vice president of the Virginia State Teachers Association.
He held this position until 1919 when he became the president of James Madison University, then called the State Normal School for Women.
[4] During his first 10 years at James Madison University, he would build Alumnae, Sheldon, Keezell, Johnston Halls and Varner House.
During his tenure, Duke would be the first president to give men degrees from James Madison University, then called State Teachers College at Harrisonburg.
On June 12, 1938, Duke renamed the school to Madison College, named after the fourth President of the United States.