He was most prominent for his service as a brigadier general on the staff of the American Expeditionary Forces headquarters during World War I.

He returned to the army for the Spanish–American War, and served as Adjutant General of New York during the governorship of Theodore Roosevelt.

[1] In 1882, Andrews began attendance at the United States Military Academy, from which he graduated in 1886, the same class which included John J.

[1] Andrews was commissioned a second lieutenant in the 5th Artillery, and served at Fort Columbus on Governors Island, New York.

[4] After resigning from the Army, Andrews was appointed Engineers officer on the staff of the New York National Guard's 1st Brigade, and commissioned as a major.

[1] In 1899, Andrews was appointed Adjutant General of New York by Theodore Roosevelt, who had won the 1898 election for governor.

[1] Following his World War I service, Andrews was appointed a brigadier general in the Organized Reserve Corps, and he served from 1921 until retiring in April, 1926.

[1] He continued to practice law and serve on corporate boards, and he remained active until retiring in 1943 and moving to Winter Park, Florida.

[1] The citation for his Army DSM reads: The President of the United States of America, authorized by Act of Congress, July 9, 1918, takes pleasure in presenting the Army Distinguished Service Medal to Brigadier General Avery DeLano Andrews, United States Army, for exceptionally meritorious and distinguished services to the Government of the United States, in a duty of great responsibility during World War I.

As Assistant Chief of Staff, American Expeditionary Forces, General Andrews has rendered most efficient service in connection with the organization and administration of the Transportation Department of the American Army in France and as Deputy Chief of Utilities in the Services of Supply.

Later, with marked ability, he headed the important administrative section of the General Staff of the American Expeditionary Forces.