John Alden Millan, 91, a retired agent of the Alcohol, Tobacco and Firearms Bureau of the Treasury Department, died of congestive heart failure Aug. 25 at the Virginian retirement home in Fairfax.

Mr. Millan was born in Fairfax and graduated from the old Oakton School. In 1924, he went to work for the Fairfax County Sheriff's Department. In 1929, he joined the federal prohibition service and remained there until 1933.

In that year, he joined what became the Alcohol, Tobacco and Firearms Bureau. He was assigned to the Washington area and later served as agent-in-charge at the offices in Richmond and Norfolk. He was assigned to the district office in Cincinnati when he retired in 1954.

Mr. Millan then lived on a farm he owned in Mathews County, Va. About 1970, he returned to Fairfax.

He was a member of the Sons of the American Revolution and the Fairfax County Historical Society.

His wife, Mary Haight Millan, died in 1964.

Survivors include two sons, Henry L., of Fairfax, and Richard F., of Oklahoma City; two daughters, Mary A. Pettitt of Palm Coast, Fla., and Ruth C. Hunley of Norfolk; a sister, Mary Page Locke of Falls Church; 10 grandchildren, and two great-grandchildren.