The Japanese bombing the U.S fleet at Pearl Harbour, Hawaii on the 7th December 1941 is what ultimatley caused the U.S to declare war during World War 2.
An economic reason for the United States to declare war on Spain in 1898 included protecting US interests in Cuba.
The US did not declare war on Germany. Germany declared war on the US shortly after the Japanese attack on Hawaii.
Pearl Harbor is the event that made them declare war.
Pearl Harbor.
google pearl harbor dumbf***
the impressment of American sailors
For one, the message the US intercepted from Germans, meant for Mexico for Mexico to declare war against the US
The immediate cause was Japan's attack on Pearl Harbor. This caused the US to declare war on Japan, which led to Germany and Italy declaring war on the US.
The attack on Pearl Harbor in Hawaii.
World War II
Gulf of Tulkon incident.
Some contend that President McKinley got angry with Spain because of the De Lome Letter, but since the Minister submitted his resignation that hardly seems like a plausible excuse to declare War. The explosion of the USS Maine appears to be a the best answer.