European nations came together at the
order to draw boundaries for the African colonies. These later
became the various African nations political borders.

Berlin Conference

Explanation:

Berlin Conference of 1884–1885 Meeting at which the major European powers negotiated and formalized claims to territory in Africa; also called the Berlin West Africa Conference.

source:  oxford reference

nativists tried to get rid of the immigrants as they thought they were going to ruin the u.s.  

"a shortage of traditional labor created new opportunities in the workplace. a major cause of the internment of japanese americans during world war ii was. racial prejudice. in the early 1940's, the "destroyers-for-military-bases deal" with great britain and the lend-lease act were evidence that the united states."