1812 in the United States
 
The following is a partial list of events from the year 1812 in the United States. After years of increasing tensions, the United States declares war on the British Empire, starting the War of 1812.
August 19: USS Constitution sinks HMS Guerriere
 
1809 in the United States
 
Events from the year 1809 in the United States.
March 4: James Madison begins the first of two terms as the fourth U.S. president
Abraham Lincoln