He attended the Braden’s Preparatory School in Highland Falls, New York and subsequently was appointed at United States Military Academy at West Point, New York in 1911. Sayler graduated four years later as a part of "the class the stars fell on" (because 59 members of this class became general officers).
During the, Sayler served as a Chief of Ordnance Officer of the European Theater of Operations. He was commissioned a Second lieutenant in Coast Artillery Corps on June 12, 1915. In 1921, he was transferred to the Ordnance Corps and subsequently served on various military posts across United States.
Sayler also attended the Command and General Staff College at Fort Leavenworth, Kansas in 1931.
In 1937, he was appointed a Chief of General Supply Division in the Office of the Chief of Ordnance and served in this capacity until the end of next year, when he was assigned to the 4th Corps Area as its Ordnance officer Then he was appointed an Ordnance officer of the First Army under the command of Lieutenant general Hugh Aloysius Drum.
In this capacity, Eisenhower tasked him to plan, assemble, and execute the logistical support for the North African invasion. During Doctorate-Day invasion he solved many problems which include waterproofing of vehicles and disposing bombs which didn"t explode.
Due to his great work at that time, United States. Forces was one of the best equipped fighting force in the history of warfare.
Sayled stayed in this capacity until 1945, when he was appointed an Assistant Chief of Ordnance, deputy of Lieutenant general, Levin H. Campbell, Junior. After the war, he was given a position as a chief at the Research and development, Ordnance Department. Sayler retired from the Army with the rank of Major general in 1949.
Major general Henry B. Sayler died on May 7, 1970 at the age of 76 in Savannah, Georgia.
Between years 1931-1937, Sayler served as a Member of the Cavalry Board.