It's never been secret. Even Wiki mentions it, barely:
----- by the way....
On December 18, 1944, the Supreme Court handed down two decisions on the legality of the incarceration under Executive Order 9066. Korematsu v. United States, a 6–3 decision upholding a Nisei's conviction for violating the military exclusion order, stated that, in general, the removal of Japanese Americans from the West Coast was constitutional. However, Ex parte Endo unanimously declared that loyal citizens of the United States, regardless of cultural descent, could not be detained without cause. In effect, the two rulings held that, while the eviction of U.S. citizens in the name of military necessity was legal, the subsequent incarceration was not—thus paving the way for their release
I asked how many Koreans and Taiwanese got caught up in internment?
I know some things about internment. It was believed at the time, to be justified in lieu of the surprise Pearl Harbor attack, vulnerability on the Pacific Coast.
My mother grew up in Los Angeles County, and they had blackouts, fearing sneak attacks by the Japanese. They harbors had nets, to block submarines from entering.
The Japanese shelled an oilfield north of Santa Barbara, named Elwood. The was a shelling in Oregon, and balloons lofted towards North America with bombs.
Finally there WERE a few subversives, and equally important, Americans were HIGHLY pissed over Pearl Harbor and internment was stated partly to PROTECT the Japanese origin folks. And military age guys were given the chance to serve in uniform, and sere bravely they did.
