[["The United States declared war on Japan on December 8, 1941, following Japan's surprise attack on Pearl Harbor on December 7. Following the U.S. declaration, Japan's allies, Germany and Italy, declared war on the United States, bringing the United States fully into World War II.", 129.0], ["In 1941, although the war began with Nazi Germany's attack on Poland in September 1939, the United States did not enter the war until after the Japanese bombed the American fleet in Pearl Harbor, Hawaii, on December 7, 1941", 116.0]]
when did america join world war two
history