What was the policy regarding Japanese Americans in the military during World War 2?

During World War II, Japanese Americans initially faced significant discrimination and were largely excluded from military service due to widespread prejudice and fear following the Pearl Harbor attack. However, this policy changed as the war progressed, leading to the formation of the 442nd Regimental Combat Team, composed mainly of Japanese American soldiers, who became one of the most decorated units in U.S. military history. Their service played a crucial role in challenging stereotypes and demonstrating loyalty, ultimately contributing to changing perceptions of Japanese Americans in the post-war era.