The drastic decrease in the overall population would be the effects of the civil war on the US regions. Option B is correct.
What is the American civil war?
The Confederate States of America, led by President Jefferson Davis, and eleven Southern slave states who declared their separation from the United States and created the "Union" fought each other in the American Civil War (1861–1865).
The Confederate States of America, a grouping of eleven southern states that seceded from the Union in 1860 and 1861, and the United States of America fought each other in the American Civil War. The long-standing dispute about the legitimacy of slavery is largely responsible for how the conflict got started.
Conflicts over federal vs. state rights, the election of Abraham Lincoln, and the economy were the causes of the Civil War. the South seceded upon Lincoln's inauguration in 1861, and the Civil War was declared to have begun
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