Answer: The United States declared war on Germany.
Step-by-step explanation:
After the rupture of diplomatic relations with Germany on Feb. 3, 1917, events pushed the United States inexorably along the road to war.
The war resolution was approved by the Senate on April 3, and by the House of Representatives on April 6. The presidential declaration of war followed immediately.
The entry of the United States was the turning point of the war, because it made the eventual defeat of Germany possible.