There was tension in the politics of the nation which were largely due to differences in the economies of the North and the South. For the South, slavery was used as a labor source hence they supported slavery. The North on the other hand was opposed to slavery as it was largely urbanized. Different regions led to the creations of different economies.
<em>Civil wars and foreign invasions showed that the empire had become too large to be ruled by one person.</em> :-)
Answer:
The Zimmerman note and unrestricted submarine warfare by Germany
Explanation:
The Zimmermann Telegram was a note from German official to offer military alliance between Mexico and Germany. President Wilson understood the diplomatic relation and broke off the relation and decided to enter the WWI.
Germany was repeatedly attacking U.S. by submarine warfare in the Atlantic that killed ore than 120 U.S. citizens on May 7, 1915 that provoked outrage in the U.S. to participate in WWI.
Hence, the two reason are The Zimmerman note and unrestricted submarine warfare by Germany.
