Army - Sergeant First Class (Retired) - Fort Polk, Los Angeles - MugThe rank title of sergeant first class (SFC) existed in the Army from 1890 [1] until 1920 when it was eliminated in an army wide simplification of enlisted ranks which had grown into a system containing 128 different rank insignia. The rank of SFC was used in several technical branches such as the Army Medical Department and in the Ordnance, Signal, and Quartermaster Corps and was equivalent to the field service ranks at the company battery troop