Us neutrality at the start of War. (July 28, 1914)
The German Occupation of Belgium (August 4, 1914)
The sinking of Lusitania (May 7, 1915)
Woodrow Wilson formally proclaims the neutrality of the United States in World War 1 because of the diversity and different sides of the United States. They didn't want to pick sides and potentially upset Americans, They were doing well and didn't need a waror any arguments between fellow Americans.
Zimmerman Telegram (1917)
Germany made plans to invade Belgium, France. The two countries refused free passage to the German troops and they were invaded on August 2 and August 4 in 1914.
Germany’s announcement of unrestricted submarine warfare (February 1917)
On May 7, 1915, a German boat torpedoed and exploded the British steamship Lusitania. It killed 1,195 people including 128 Americans,
The US economic interest in the war - we aid the Triple Entente/Allies (1914 - joining the war)
In 1917, a german foreign secretary intended to write a letter to a German ambassador to Mexico and the British code breakers intercepted it. British de-coded it and handed it to the Americans because it was a letter on how they were gonna attack America.
On February 1, 1917, the lethal threat of the German U-boat submarine was set out on the sea again to attack the British after being restricted.
When war broke out in Europe, the US business and economic industries were quickly weakening. At the same time, there was so much opportunity and potential ahead. Prices at the time skyrocketed.