I read somewhere the Seward advised Lincoln to start a war with Britain and conquer Canada instead of fighting a war with the South over slavery.
Seward's somewhat idiotic notion was for the USA to pick a fight with UK. This would cause a great outburst of patriotism in southern states, which would de-secede from the CSA, rejoining the Union to fight Britain.
Wouldn't have worked, of course. Southern strategy for gaining independence was largely based on the idea that UK would support it to get the cotton it needed.