Question

What were the causes of World War I, and why did the United States enter
the war?

Answer 1

The United States later declared war on German ally Austria-Hungary on December 7, 1917. Germany's resumption of submarine attacks on passenger and merchant ships in 1917 became the primary motivation behind Wilson's decision to lead the United States into World War I.

Step-by-step explanation:

Answer 2

World War one started because of the assassination of Archduke Franz Ferdinand. Russia went in mobilization because of the alliance with Serbia. When Russia did that, Germany declared war on Russia. The United States joined because they did not want a war that might destroy them and their allies.