Britain joins the Confederacy

[WillK]

Could the Confederacy have won the American Civil War if they had managed to get Britain to interfere on their side in 1862?
What would likely have happened on the US/Canadian border? Would the US have tried any offensive moves against the British or merely trying to defend?

I think it likely that the US/Canadian border would have been defensively held by both with any  action happening at sea or along the coast of the southern US.