Three sleeve rank insignia
When the United States entered World War I, enlisted sleeve rank insignia contained the branch symbol. Private First Class was represented by simply the Engineer castle on a circle, while an Engineer Senior Master Sergeant wore a castle with a star above and a wreath below. Also displayed are the stripes of an Engineer Corporal. In September of 1918 the Army ended the use of branch insignia and standardized all NCO sleeve ranks as simple stripes.