@gollum,
The 442nd RCT/100th Battalion operated in Italy, and then in southern France. (They were not deployed against the Japanese.) They achieved their greatest fame while the war was still being waged by fighting through German lines in southern France to rescue a battalion of the 36th Division, the Texas National Guard division. That unit had already gotten headlines when they were surrounded by the Germans, got cut off and became known as "the Lost Battalion."
There were about 127,000 ethnic Japanese in the continental United States, of which 110,000 or 120,000 (sources vary on the exact number) were interned. They represented just under half of the ethnic Japanese population of the United States. There were about 150,000 ethnic Japanese in Hawaii, of which only about 2000 were interned. Ethnic Japanese were about a third of the population of Hawaii, so it would have been a nightmare to attempt to intern most of them, as had happened on the west coast. There was also not the ingrained racism of the west coast.
Long before the war, the first Roosevelt president, Theodore Roosevelt, had had to deal with institutionalized racism on the west coast. In 1906, San Francisco required Japanese students to be educated in separate, segregated schools. The Japanese were pretty pissed about that, understandably. It didn't go away, either. In 1919, an Anti-Japanese League was formed in Seattle, Washington. The attitude was widespread on the Pacific coast of the United States. So, there was very little internment in Hawaii, where more than half of all the ethnic Japanese in the United States lived, but almost total internment on the west coast--anywhere from 86% to 95%, depending on whose population figures for the internment camps one uses.
FM pointed out that ethnic Germans were interned earlier in the thread, I stood by my statement that the Germans were not subjected to the same penalties. Ethnic Germans who were interned were interned after judicial review on a case by case basis. Ethnic Japanese on the west coast were interned because they Japanese, regardless of age, gender or putative political activities. The entire population of ethnic Germans in the United States who were born in German was more than ten times as great as ethnic Japanese of all categories in the continental United States (once again, this excludes the Japanese in Hawaii--who were, apparently, not seen as a problem in Hawaii). If you include ethnic Germans, both of whose parents were born in Germany, or only one of whose parents had been born in Germany--there were about one hundred times as many ethnic Germans in the continental United States as there were ethic Japanese; even if you include the Japanese of Hawaii, there were still more than 40 times as many ethnic Germans as ethnic Japanese--yet ten times as many Japanese were interned as were Germans. You'd have to be a complete idiot not to recognize the racist nature of the policy.
The U.S. Army and Army Air Force were segregated in that war. The Navy and Marine Corps were not segregated, but blacks were almost never put into combat roles. (Since the war, it has been recognized that blacks on naval vessels, who were cooks and stewards, but who manned [segregated] anti-aircraft batteries aboard their ships, showed exemplary courage and devotion--many were decorated, alas, far too many posthumously.) The armed forces were desegregated by President Truman in January, 1948.