June 18, 1812: The day after the Senate followed the House of Representatives in voting to declare war against Great Britain,
President James Madison signed the declaration into law—and
the War of 1812 began.

The American war declaration, opposed by a sizable minority
in Congress, had been called in response to the British
economic blockade of France, the induction of American
seaman into the British Royal Navy against their will,  and
the British support of Indian tribes along the Great Lakes  
frontier.     

A faction of Congress known as the “War Hawks” had
been advocating war with Britain for several years and
had not hidden their hopes that a U.S. invasion of Canada
might result in significant territorial land gains for the
United States.