Source: Thomas Jefferson to John Randolph, April 22, 1820 [T]his momentous question, like a firebell in the night, awakened and filled me with terror. I considered it, at once as the [death] knell of the Union. It is hushed, indeed, for the moment. But this is a reprieve only, not a final sentence. A geographical line, coinciding with a marked principle, moral and political, once conceived and held up to the angry passions of men, will never be obliterated; and every new irritation will mark it deeper and deeper.

Source: Thomas Jefferson to John Randolph, April 22, 1820 [T]his momentous question, like a firebell in the night, awakened and filled me with terror. I considered it, at once as the [death] knell of the Union. It is hushed, indeed, for the moment. But this is a reprieve only, not a final sentence. A geographical line, coinciding with a marked principle, moral and political, once conceived and held up to the angry passions of men, will never be obliterated; and every new irritation will mark it deeper and deeper.