Why did the US get involved in WWll

Events

11/11/1918
1934 - 1936
1935 - 1937
1937 - 1941
Approx. 1937
Dec 12 1937
September 1939

Events2

1940
1940
1940
Approx. 1940
Sep 1940
September 2, 1940
11 Mar 1941

Events 3

December 29, 1940
1941
1941
January 6, 1941
August 14, 1941
December 7, 1941
December 8, 1941