The constant conflict between Britain and France from the end of the 18th century onwards created significant grievances for America, which had relations with both countries, as Britain adopted oppressive maritime practices to block the neutral US from trading with France.
When the U.S. demanded an end to the interference, Britain refused. As a result the U.S. declared war on June 18, 1812.
The war quickly grew unpopular and on December 24th, the two states signed the Treaty in Belgium. It restored the status quo antebellum (before the war) and was a turning point for the growth of US nationalism, marking a decline of American dependence on Europe.