Argentina is also perfect through two games after a 21-10 victory over Uruguay.
Despite the win, Canadian coach Kieran Crowley says there's plenty of room for improvement.
"I think our skill let us down big time," Crowley said. "We put the pressure on (the Americans) by running hard at them but then we couldn't execute and our finishing wasn't good enough."
Connor Braid got Canada on the board with a third-minute penalty, which was matched four minutes later by a penalty kick from Zach Pangelinan of the U.S.
Canada went ahead 6-3 at the half hour mark but the pressure was beginning to mount on the visitors as a series of troublesome scrums from five metres out eventually saw a penalty try awarded to Canada on 36 minutes.
With the Braid conversion Canada held a comfortable 13-3 lead at the break.
Jordan Wilson-Ross and Clayton Meeres then hit for tries in the 58th and 63rd minutes to put Canada in front 23-3.
Tempers then began to fray as Meeres was given a yellow card for leading with his shoulder on a tackle in the 66th minute. But just two minutes later a full on tackle of Wilson-Ross by his long hair saw John Quill of the U.S. receive a red card.
Canada takes on Argentina to determine first place on Saturday, while the U.S. (0-2) and Uruguay (0-2) will square off to determine third and fourth place.