4. Explain the causes of the American entrance into World War I.

Zimmermann telegram- Nothing like negotiating with a neighbor to invade their front lawn.

Unrestricted submarine warfare- Sinking ships owned by the US constantly is already making us angry.

and the sinking of the Lusitania- Now this wasn't the final straw but it did indeed shake US support for Germany and caused outrage all over the USA.

The U.S. entered World War 1 because Germany embarked on a deadly gamble. Germany sank many American merchant ships around the British Isles which prompted the American entry into the war