Picture brides were not only Korean thing at the time. Chinese and Japanese immigrants were doing the same. Also, during WW2, the Japanese American internment is not well known to Koreans. There were 6000 Japanese American, Nisei soldiers in the US military that helped the ally win the Pacific war against imperial Japan. The 442nd RCT, the all Japanese American, Nisei, army unit, was also in the European front fighting the Nazis.