The United States fought Germany, Italy, and Japan in World War II. The United States entered World War II because Japan bombed the U.S. at Pearl Harbor in 1941. Japan was an ally of Germany and Italy. Together they formed the "Axis powers." The United States and its allies won the war in 1945 against Germany, Italy, and Japan.
Section "Learn and Explore" uses official instructions and media files of US Citizenship and Immigration Services, US National Museum of American History, The Smithsonian Institution and other governmental and public organization.