Answer: The United States joined World War 1 because Germany’s resumptions of submarine attacks in 1917 on passenger’s and merchant ships.

3 reasons why the U.S. entered ww1

The United States joined World War 1 due to:

German submarine attacks:

• Germany’s unrestricted submarine warfare, which led to the sinking of American ships and loss of lives, angry the United States to join the war.

Zimmerman Telegram:

• The interception of the Zimmerman Telegram, in which Germany proposed a military alliance with Mexico against the United States, further pushed the U.S. towards war.

Support

• The U.S. had friends in Europe and wanted to help them, so it joined the war on their side.

When did U.S declare war on Germany ww1

On April 6, 1917, the United States officially declared war on Germany in World War 1. This decision came after a series of events that strained relations between the two countries.