Early in 1917, the Post Office was caught off guard by a sudden huge demand for high-value stamps. At that time, Americans were sending many shipments of machine parts to Russia by Parcel Post. Also, valuable shipments of Liberty Bonds required large amounts of postage.
 
To meet demand, the 1918 $5 Franklin stamp was issued. The bi-color stamp features a deep green frame and black central design on unwatermarked paper. The perforation gauge had been changed to 11 the previous year, which defines this sixth major set in the Washington-Franklins