There's a lot of reasons. One big reason is the sinking of the Lusitania.
World War 2
The US joined the war on the side of the Allies on April 6, 1917.
archduke ferdinand
The US entered when it declared war on Germany on April 6th 1917. So they entered late.
tu madre
The US did enter World War 1, though not till 1917.
One of the main reasons the US entered World War I on the side of the allies was because the Germans had sunk the Lusitania, a passenger ship containing many Americans.
To prevent the spread of communism
1. Germany invaded Poland 2. Japan Bombed pearl harbor
the us decided to enter world war because they want the resources of france, and they want to keep on ruling france.
To help out other countries
1941
No
1917 smart
1941
pearl harbor