The battle was at Pearl Harbor, and it was a surprise attack by the Japanese on the Americans. This led to the US declaring war on the Axis powers, and it led to the Japanese-Americans being put inside internment camps located in like the middle~of~nowhere inside USA because the US was afraid that the Japanese-Americans would give out information and feel loyalty to their homeland, Japan.
SOOOOO in the end .....
The United States entered World War II because Japan attacked its Navy.
Hop this helps:)))