The United States entered World War II after the Japanese attack on Pearl Harbour on 7th December 1941. The US declared war on the following day, 8th December 1941.
The us entered ww2 in 1941
World War 2
The US entered World War 1 on April 6, 1917. The war ended about one and a half years later.
The US joined the war on the side of the Allies on April 6, 1917.
The US entered when it declared war on Germany on April 6th 1917. So they entered late.
on decmber 8 1941
1909 to 1944 The US entered World War 2 in December of 1941.
The United States declaration of war is from 6 April 1917.
The US did enter World War 1, though not till 1917.
the us decided to enter world war because they want the resources of france, and they want to keep on ruling france.
The United States joined the Second World War in December 1941 as a response to the Japanese attack on Pearl Harbour.