dec 30, 1860 - South Carolina secedes from the Union

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The convention then adjourned to Charleston to draft an ordinance of secession. When the ordinance was adopted on December 20, 1860, South Carolina became the first slave state in the south to declare that it had seceded from the United States.

Source: https://en.wikipedia.org/wiki/South_Carolina_in_the_American_Civil_War

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