1 Dollar Military Payment Certificate

Series 521, issued from 1958 to 1961, was the fourth MPC series produced after World War II. MPCs were designed specifically to control black market currency exchange in occupied and combat zones — soldiers were paid in them, and conversion to local currency was tightly regulated. When a series was retired, unannounced "conversion days" gave authorized personnel a narrow window to swap old notes for new ones, deliberately freezing out black market operators who had accumulated large stocks.

Tudor Press, a Boston firm, handled printing for several MPC series before the program eventually shifted to the Bureau of Engraving and Printing.