The principal lever relied on by the insurgents for exciting foreign nations to hostility against us, as already intimated, is the embarrassment of commerce. Those nations, however, not improbably saw from the first that it was the Union which made as well our foreign as our domestic commerce. They can scarcely have failed to perceive that the effort for disunion produces the existing difficulty, and that one strong nation promises more durable peace and a more extensive, valuable, and reliable commerce than can the same nation broken into hostile fragments.

First State of the Union address (1861)