Please discuss events that led the United States into WWI.These could include Germany's submarine wafare, US trade with England and France, and the...

The last answer by 'revolution' is incorrect. the 'Lusitania' was sunk on March 7th 1915, Unrestricted Submarine Warfare began on February 1st 1917 and the US declared war on April 6th 1917. The sinking of the 'Lusitania' made Americans angry but since Germany paid the American families for their losses and said they would not do this again all was forgiven. However, German did do this again with the sinking of the British ship the 'Arabic' (8/15) and the French ferry the 'Sussex' (4/16), so to end this conflict Germany agrees not to sink British passenger ships, only cargo ones.

For some reason though, Germany decides that even though it is winning the war (Russia has dropped out and the French are pushed almost to Paris) that it will declare Unrestricted Submarine Warfare which meant that they would blow up all ships in the warzone whether they were allied with Britain or not.

Finally, the Zimmerman Telegraph/Note is what really pushed the US to war. This stated that "we (Germany) intend to begin unrestricted submarine warfare on the first of February. We shall endeavor in spite of this to keep the United States neutral. In the event of this not succeding, we make Mexico a proposal of alliance on the following basis; make war together, make peace together, generous financial support, and an understanding on our part that Mexico is to reconquer the lost territory in Texas, New Mexico and Arizona."

Although Mexico declined Germany's offer, this promise of US territory to Mexico was a direct threat even though the US was not supposed to know about this (Britain intercepted this telegraph and passed it to the US) because it said that if the US joined the war then Germany would take its land and give it away.

So after Unrestricted Submarine Warfare and the Zimmerman Telegraph the US had no reason other than the usual (death, cost, time, etc) not to go to war with Germany. The war was also a way to strengthen its ties with Great Britain and assert itself as a Great Power in the Great Power Rivalry.

I hope this helps!