10 Dollars Military Payment Certificate

Military Payment Certificates were a deliberate instrument of economic control, not a convenience. The U.S. military introduced them after World War II specifically to prevent black-market dollar convertibility — local currency speculators had exploited GIs' greenbacks extensively in occupied Europe, and the Pentagon was determined not to repeat that in Southeast Asia. MPC series were periodically invalidated without warning in operations called "C-Day" or "conversion day," on which all MPC in circulation had to be exchanged simultaneously, instantly stranding any locals holding notes they'd obtained illegally.

Series 641, the designation covering this note's issue period, circulated primarily in Vietnam, Japan, Korea, and a handful of other U.S. military installations across the Pacific. Conversion to Series 661 in April 1968 gave holders roughly one day to comply.