HONOLULU — Herbert Yanamura is an American, born and raised among the coffee farms of Hawaii’s Kona district. Yet the U.S. government branded him an “enemy alien” after the 1941 bombing of Pearl Harbor because he looked like the invaders.

So Yanamura volunteered to join the Army to prove his loyalty.

Nearly 70 years later, that same government honored him and the thousands of other Japanese-Americans who served in World War II with one of its most elite rewards: the Congressional Gold Medal....