Japanese American internment
In February 1942, President Franklin D. Roosevelt signed Executive Order 9066. This order said that people who lived in some parts of the country could be taken out of those areas for any reason. While the order did not use the exact words "Japanese Americans", people knew that those were the people who would be taken out of those areas.  The areas included all of California and the western parts of Oregon, Washington, and Arizona.  (See the area marked "exclusion zone" on the map on this page.)  This was where most Japanese Americans lived at that time.