The West Coast was divided into military zones, and on February 19, 1942, President Franklin D. Roosevelt issued Executive Order 9066 authorizing exclusion. Congress then implemented the order on March 21, 1942, by passing Public Law 503.he West Coast was divided into military zones, and on February 19, 1942, President Franklin D. Roosevelt issued Executive Order 9066 authorizing exclusion. Congress then implemented the order on March 21, 1942, by passing Public Law 503.