Answer:
Prohibiting slavery in the territories.
Explanation:
According to the ruling it was decided that Congress had exceeded their authority when ratifying the Missouri Compromise, and therefore "had no power to forbid or abolish slavery in the territories west of Missouri and north of latitude 36°30" (Britannica.com).
1)Germans sinking US merchant ships taking supplies to England
2)Japan's unreasonable demands on the United States (re- instating oil sales and dropping support of the Philipeenes and China)
3)German submarines beginning to shoot at US war ships
4)England and France are typically our allies so we were going to enter the war eventually anyway
5)Pearl Harbor was obviously why we entered the war.
Powers not delegated to the U.S by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.
So basically, they are reserved to the states and left up to them to decide.
