Why did America enter WWI?

In the start of WWI America was neutral and could afford to do so as they were across an ocean from the conflicting European countries. Even though they were not militarily involved in the war, America as a nation, seemed to largely side with the British and French people. The American government did not oppose the British blockade enacted against the German government and even sold weapons to the allies side of the war, while they greatly opposed the German use of submarines to break the blockade. The Germans knew that if the U.S joined the war it would be on the side of the French and British and so they obeyed the American order to seize unrestricted submarine warfare to prevent the added support of the Americans on their opposers side. When a German submarine sinked the British Lusitania and killed 128 Americans aboard the ship, President Woodrow Wilson demanded that the Germans follow the established rules of submarine warfare (that did not benefit the Germans) or there would be a risk of war.

 In the Election of1916 Wilson won because of his popularity gained by "keeping the country out of war", in his mind he was prepared to go to war as he watched the progression of events in the war and his reelection allowed him to prepare for war. He believed that if America were to be involved in war it would be for progressive ideals. He promoted ideas like "Peace among equals" and "peace without victory". He thought of America as a country of democracy and believe the world would only be safe with democracy in all nations.

 The Germans knew America was not neutral and they felt the need to win the war soon as they were running out of resources and were afraid of the American engagement in the war. They saw submarines as the way to win the war and so on February 1,  1917 the German government declared they would sink all ships around Great Britain. This was one trigger to the American entrance to WWI. The Zimmerman note was the next trigger that caused America to enter war. It was discovered that Germany had contacted Mexico, encouraging it to declare war on America if it were to enter the war with the incentive of Mexico being able to claim land they lost to America. This largely angered the American public, who already had a negative image of the Germans, due to the propaganda by France and Britain. 

The final straw was when a German submarine attack sinked several American ships. President Wilson, not long after, requested congress declare war. Wilson brought up his point that "the world was be safe for democracy" and he strongly believed in this as he lead the country into a war against the Germans with the British and French. There were many reasons America sided with the British and French in WWI. I only touched on some, but what were other reasons why America would side with the allies?