Invasions by Barbarian Tribes
The extension of slavery into the territories split the Democratic party and the Whig party, and opponents of the Kansas-Nebraska Act of 1854 organized the new Republican party. Basically just the unwanted extension of slavery.
Answer:
The Truman Doctrine demonstrated that the United States would not return to ... both economically and militarily to contain the spread of communism around the world. ... One of the most pressing problems in the immediate aftermath of World War II ... in combatting the spread of communism: economic aid or military force?
Explanation:
It restricted colonial B) trade
