Final answer:
Based on the provided information, we cannot determine the year the Inter-American Defense Board Medal was authorized; students should consult relevant military history texts or official records.
Step-by-step explanation:
The question relates to a specific historical event regarding a military decoration known as the Inter-American Defense Board Medal. However, the provided information does not include the year when the Inter-American Defense Board Medal was authorized. None of the references mentioned discuss this medal or its authorization year directly. Consequently, based on the information given, we cannot determine the year when the Inter-American Defense Board Medal was authorized. Students are advised to look for this historical event in relevant military history texts or official military decoration records for the most accurate information.