The Canadian team, led by skip Rachel Homan, shrugged off their disappointment at the semi-final defeat by Scotland, who will face Sweden in the gold medal match.
Homan scored three points in the third end to take a 4-2 lead which they never gave up, and Canada kept control to win in the 10th end.
Canada's skip, Rachel Homan, was delighted with her team's response after the disappointment of losing the semi-final on the last stone.
"I'm really proud of my team for going out there and re-grouping after last night, going out there today and playing real strong," she said.
"It sucks to lose, but for us to come back and win like we did, I'm really proud of that.
USA skip Erika Brown said: "We weren’t as sharp. Just some half shots here and there when we really needed to put the pressure on them and make their shots a little bit tougher. We weren’t able to do that today. They played great. They played really well today and we needed a few really big shots."