The correct answer is that the bombing of Pearl Harbor in 1941 by Japan made American isolationists quickly change their tune as America was under attack. Once Germany declared war on the US, the US was fully into the war.
Answer:
Slavery played the central role during the American Civil War. The primary catalyst for secession was slavery, especially Southern political leaders' resistance to attempts by Northern antislavery political forces to block the expansion of slavery into the western territories.
Why is slavery wrong?
Slavery increases total human unhappiness.
The slave-owner treats the slaves as the means to achieve the slave-owner's ends, not as an end in themselves.
Slavery exploits and degrades human beings.
The answer is Berlin, but some info
The USSR got the western bit, and the US, Great Britain, and France decided to combine their parts together, forming East Berlin
