Why did President Lincoln's argument that secession was not constitutional? -He believed secession would weaken the country and make it susceptible to foreign attacks.
-He encouraged Congress to pass a law prohibiting secession in any form, and so it was illegal.
-The Constitution had a clause listing the United States as a "perpetual Union" that could not end.
-The Constitution explicitly stated that secession was unconstitutional

there are no mutiple choices here

world war i began in 1914, after the assassination of archduke franz ferdinand, and lasted until 1918. during the conflict, germany, austria-hungary, bulgaria and the ottoman empire (the central powers) fought against great britain, france, russia, italy, romania, japan and the united states (the allied powers). to new military technologies and the horrors of trench warfare, world war i saw unprecedented levels of carnage and destruction. by the time the war was over and the allied powers claimed victory, more than 16 million people—soldiers and civilians alike—were dead.

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