Period: 1939-09-01 - 1945-09-02

In the spring of 1941, President Franklin D. Roosevelt ordered the Navy to patrol ship lanes to Europe. By July, U.S. warships were conveying, and by September were attacking German submarines. In November, the Neutrality Act was partially repealed to protect U.S. military aid to Britain. On December 8, 1941, the United States declared war with Japan, on Dec. 11 with Germany and Italy, and on June 5, 1942, with Bulgaria, Hungary and Romania. The United States declared war against Japan after the surprise bombing of Pearl Harbor, and against Germany and Italy after those nations, under the dictators Hitler and Mussolini, declared war against the United States.