"equal protection under the law" means that everyone has the right to be equal under the law (constitution). That also means that no matter what race or ethnicity, everyone will get treated equally.
So for example, if someone commit a crime, they would be punished under the law, no matter what race that person is.
they met at the Arcadia Conference in Washington, D.C. At this conference, the two leaders agreed on a strategy known as "Germany First" in which they agreed to concentrate their war efforts