World War II started on September 1, 1939, with the German invasion of Poland. With war already raging in Asia, the invasion sparked a global conflict that lasted until 1945. The Axis Powers fought relentlessly against the Allied Powers for dominance around the world. The United States remained neutral in the war until Japan, a member of the Axis Powers, attacked an American naval base at Pearl Harbor, Hawaii, on December 7, 1941. In response to the attack and a dramatic speech by President Franklin Delano Roosevelt, the U.S. Congress declared war on Japan on December 8, 1941. Three days later, the United States declared war on Germany and Italy.
