What was one of the major wars of the 1900s that the United States fought in?
World War I.
In what year did the United States officially enter World War I?
In \(1917\). The war itself had been ongoing since \(1914\).
What was a primary reason for the United States to enter World War I?
Germany's policy of unrestricted submarine warfare, which resulted in the sinking of American merchant ships.
What was the name of the British passenger ship sunk by a German submarine in \(1915\), which killed over \(100\) Americans and fueled anti-German sentiment?
The Lusitania.
What was the Zimmermann Telegram?
A secret message from Germany to Mexico proposing a military alliance against the U.S. if the U.S. entered the war. It was intercepted and published, outraging Americans.
Which alliance did the United States join in World War I?
The Allied Powers (also known as the Entente Powers).
Who were the main Allied Powers that the U.S. joined?
Great Britain, France, and Russia (though Russia left the war shortly after the U.S. entered).
Who were the main countries of the opposing side, the Central Powers?
Germany, Austria-Hungary, and the Ottoman Empire.
How did the U.S. entry into the war impact its outcome?
The influx of fresh American troops and resources helped tip the balance in favor of the Allies, leading to their victory in \(1918\).
On what date did Congress formally declare war on Germany, marking U.S. entry into WWI?
