What was one of the goals of the united states during the war of 1812?

There were multiple goals. Stampeded by a group of legislators known as the War Hawks, the United States launched the war of 1812 to invade and forcibly annex Canada, something Thomas Jefferson called "a mere matter of marching." He was wrong. Canadian militia and natives made up 75% of the defenders -- the remainder being British regulars -- and that greatly outnumbered force inflicted a series of decisive defeats on the invaders, who fled back over the border and beyond, surrendering Detroit, Buffalo, and Fort Dearborn (Chicago).
The other goal was to break the power of the Indian confederacy whose homeland blocked America's westward expansion. In that goal, the US succeeded, because the British abandoned their native allies.