USA had to join the war after altercations and provocations by the Germans.
Explanation:
America had remained neutral for almost all of the war until their trade ships began being sunk by the Germans as USA was a major supplier of arms to the nations and then their trade routes were purposefully blocked.
There was also a plan revealed in the Zimmermann note about a conspiracy to get Mexico to declare war on the USA effectively starting a home front in the war for US.
This was what led US to get involved in the war directly.
Southern states were critical to the war effort during World War II (1941-45) and none more so than Georgia. Some 320,000 Georgians served in the U.S. Armed Forces during World War II, and countless others found employment in burgeoning wartime industries. Their experiences were pivotal in determining the state's future development, and the war itself marked a watershed in Georgia's history. Because it occurred when important shifts in the state's politics, race relations, and economy were already under way, the war accelerated Georgia's modernization, lifting it out of the Great Depression<span> and ushering it into the mainstream of American life.</span>
