because World War 1
Post-War labor disputes
The Great Depression and certain consequences from from WWI created a fear of entering another World War so Isolationism was America's best bet. - Dr. Wiener
The attack on Pearl Harbour, by the Japanese, directly brought the USA into the second World War. America declared war on Japan, and then Germany declared war on the USA, some days later.
by exchange of stake
America joined the Great War, or World War I, primarily due to several factors, including unrestricted submarine warfare by Germany, which threatened American commercial shipping and led to the sinking of ships like the Lusitania. The interception of the Zimmermann Telegram, in which Germany proposed a military alliance with Mexico against the U.S., also fueled public outrage. Additionally, there was a growing sentiment to support the Allies, particularly Britain and France, in their struggle against German aggression. These factors combined to shift public opinion and political will towards entering the conflict in April 1917.
Its World War 1 u idiot...
They were pushed by war and cultural divides (communism).
There has never been a war between America and England.
The bombing of Pearl Harbor on December 7, 1942.
German U-boats sunk the the Ship the Lusitania. It was carrying American civilians. America was close to joining the war, this just pushed America into it faster and on the side of England.
Great Britain and America
Great
Depends on a variaty of factors
The War of 1812 was between the USA and Great Britain.
They pushed public opinion until McKinley had no choice but to start war. It stirred up tensions between Spain and America. They reported heavily on Spanish atrocities in Cuba, gaining public support for the war.
Because of the US Civil War the process was pushed forward with great haste.
Great Britain